Example usage for org.objectweb.asm MethodVisitor visitVarInsn

Introduction

In this page you can find the example usage for org.objectweb.asm MethodVisitor visitVarInsn.

Prototype

public void visitVarInsn(final int opcode, final int var) 

Source Link

Document

Visits a local variable instruction.

Usage

From source file:com.nginious.http.xsp.expr.SubstrFunction.java

License:Apache License

/**
 * Creates bytecode for evaluating this substring function. The specified method visitor
 * and type are used for generating bytecode.
 * /*  w ww  .  j  a  v  a  2s . co m*/
 * @param visitor the method visitor
 * @param type the type
 */
void compile(MethodVisitor visitor, Type type) {
    value.compile(visitor, Type.STRING);
    visitor.visitVarInsn(Opcodes.ASTORE, 1);
    value2.compile(visitor, Type.INT);
    visitor.visitVarInsn(Opcodes.ISTORE, 2);
    value3.compile(visitor, Type.INT);
    visitor.visitVarInsn(Opcodes.ISTORE, 3);

    Label nullLabel = new Label();
    Label notNullLabel = new Label();

    // check for null string
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitJumpInsn(Opcodes.IFNULL, nullLabel);

    // start < 0
    Label label1 = new Label();
    visitor.visitLdcInsn(0);
    visitor.visitVarInsn(Opcodes.ILOAD, 2);
    visitor.visitJumpInsn(Opcodes.IF_ICMPLT, label1);
    visitor.visitLdcInsn(0);
    visitor.visitVarInsn(Opcodes.ISTORE, 2);

    // start > value.length
    Label label2 = new Label();
    visitor.visitLabel(label1);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "length", "()I");
    visitor.visitVarInsn(Opcodes.ILOAD, 2);
    visitor.visitJumpInsn(Opcodes.IF_ICMPGT, label2);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "length", "()I");
    visitor.visitVarInsn(Opcodes.ISTORE, 2);

    // end < start
    Label label3 = new Label();
    visitor.visitLabel(label2);
    visitor.visitVarInsn(Opcodes.ILOAD, 2);
    visitor.visitVarInsn(Opcodes.ILOAD, 3);
    visitor.visitJumpInsn(Opcodes.IF_ICMPLT, label3);
    visitor.visitVarInsn(Opcodes.ILOAD, 2);
    visitor.visitVarInsn(Opcodes.ISTORE, 3);

    // end > value1.length
    Label label4 = new Label();
    visitor.visitLabel(label3);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "length", "()I");
    visitor.visitVarInsn(Opcodes.ILOAD, 3);
    visitor.visitJumpInsn(Opcodes.IF_ICMPGT, label4);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "length", "()I");
    visitor.visitVarInsn(Opcodes.ISTORE, 3);

    // substr
    visitor.visitLabel(label4);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitVarInsn(Opcodes.ILOAD, 2);
    visitor.visitVarInsn(Opcodes.ILOAD, 3);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "substring", "(II)Ljava/lang/String;");
    visitor.visitJumpInsn(Opcodes.GOTO, notNullLabel);

    visitor.visitLabel(nullLabel);
    visitor.visitInsn(Opcodes.ACONST_NULL);

    visitor.visitLabel(notNullLabel);

}

---

From source file:com.nginious.http.xsp.ForEachTagPart.java

License:Apache License

/**
 * Creates bytecode for this for each tag part using the specified class writer and method visitor.
 * /*  w  w w . j  a  va  2s.co m*/
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @param visitor the method visitor
 * @throws XspException if unable to create bytecode
 */
void compile(String intClassName, ClassWriter writer, MethodVisitor visitor) throws XspException {
    if (this.setValue == null) {
        throw new XspException(
                "Attribute set is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    if (this.varName == null) {
        throw new XspException(
                "Attribute var is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    this.methodName = "forEach" + methodNameCounter.getAndIncrement();
    visitor.visitVarInsn(Opcodes.ALOAD, 0);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitVarInsn(Opcodes.ALOAD, 2);
    visitor.visitVarInsn(Opcodes.ALOAD, 3);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, intClassName, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V");
}

---

From source file:com.nginious.http.xsp.ForEachTagPart.java

License:Apache License

/**
 * Creates bytecode in a separate method for evaluating this for each tag part.
 * //from w  w w .j  a v  a  2  s  . co  m
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @throws XspException if unable to create bytecode
 */
void compileMethod(String intClassName, ClassWriter writer) throws XspException {
    String[] exceptions = { "com/nginious/http/xsp/XspException" };
    MethodVisitor visitor = writer.visitMethod(Opcodes.ACC_PRIVATE, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V", null,
            exceptions);
    visitor.visitCode();

    Label tryLabel = new Label();
    Label startCatchLabel = new Label();

    // Start try block
    visitor.visitTryCatchBlock(tryLabel, startCatchLabel, startCatchLabel, "java/lang/Exception");
    visitor.visitLabel(tryLabel);

    try {
        String expression = setValue.getExpressionContent();
        ExpressionParser parser = new ExpressionParser();
        TreeExpression expr = parser.parse(expression);

        if (expr.getType() != Type.ANY) {
            throw new XspException("Expression in attribute set in tag " + getName()
                    + " is not an attribute or bean property " + " at line " + getLocationDescriptor());
        }

        expr.compile(visitor, Type.ANY);
        visitor.visitTypeInsn(Opcodes.CHECKCAST, "java/util/Collection");
        visitor.visitVarInsn(Opcodes.ASTORE, 4);
    } catch (ExpressionException e) {
        throw new XspException("Invalid expression in attribute set in tag " + getName() + " at line "
                + getLocationDescriptor(), e);
    }

    Label labelOut = new Label();
    visitor.visitVarInsn(Opcodes.ALOAD, 4);
    visitor.visitJumpInsn(Opcodes.IFNULL, labelOut);

    // Start
    if (this.start != null) {
        start.compile(visitor, Type.INT);
    } else {
        visitor.visitLdcInsn((int) 0);
    }

    visitor.visitVarInsn(Opcodes.ISTORE, 5);

    // End
    if (this.end != null) {
        end.compile(visitor, Type.INT);
    } else {
        visitor.visitVarInsn(Opcodes.ALOAD, 4);
        visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Collection", "size", "()I");
    }

    visitor.visitVarInsn(Opcodes.ISTORE, 6);

    // Step
    if (this.step != null) {
        step.compile(visitor, Type.INT);
    } else {
        visitor.visitLdcInsn((int) 1);
    }

    visitor.visitVarInsn(Opcodes.ISTORE, 7);

    // Current pos
    visitor.visitLdcInsn(0);
    visitor.visitVarInsn(Opcodes.ISTORE, 8);

    visitor.visitVarInsn(Opcodes.ALOAD, 4);
    visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Collection", "iterator",
            "()Ljava/util/Iterator;");
    visitor.visitVarInsn(Opcodes.ASTORE, 9);

    Label labelStart = new Label();

    // Start of loop
    visitor.visitLabel(labelStart);

    // iterator.hasNext();
    visitor.visitVarInsn(Opcodes.ALOAD, 9);
    visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Iterator", "hasNext", "()Z");
    visitor.visitJumpInsn(Opcodes.IFEQ, labelOut);

    // iterator.next();
    visitor.visitVarInsn(Opcodes.ALOAD, 9);
    visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Iterator", "next", "()Ljava/lang/Object;");
    visitor.visitVarInsn(Opcodes.ASTORE, 10);

    // pos >= start && pos <= end && (pos - start) % step == 0
    Label labelIncr = new Label();

    visitor.visitVarInsn(Opcodes.ILOAD, 8);
    visitor.visitVarInsn(Opcodes.ILOAD, 5);
    visitor.visitJumpInsn(Opcodes.IF_ICMPLT, labelIncr);

    visitor.visitVarInsn(Opcodes.ILOAD, 8);
    visitor.visitVarInsn(Opcodes.ILOAD, 6);
    visitor.visitJumpInsn(Opcodes.IF_ICMPGT, labelIncr);

    visitor.visitVarInsn(Opcodes.ILOAD, 8);
    visitor.visitVarInsn(Opcodes.ILOAD, 5);
    visitor.visitInsn(Opcodes.ISUB);
    visitor.visitVarInsn(Opcodes.ILOAD, 7);
    visitor.visitInsn(Opcodes.IREM);
    visitor.visitJumpInsn(Opcodes.IFNE, labelIncr);

    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    varName.compile(visitor, Type.STRING);
    visitor.visitVarInsn(Opcodes.ALOAD, 10);
    visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "com/nginious/http/HttpRequest", "setAttribute",
            "(Ljava/lang/String;Ljava/lang/Object;)V");

    // Call sub parts
    for (XspPart part : this.contentParts) {
        part.compile(intClassName, writer, visitor);
    }

    // pos++
    visitor.visitLabel(labelIncr);
    visitor.visitIincInsn(8, 1);
    visitor.visitJumpInsn(Opcodes.GOTO, labelStart);

    visitor.visitLabel(labelOut);
    visitor.visitInsn(Opcodes.RETURN);

    visitor.visitLabel(startCatchLabel);

    visitor.visitVarInsn(Opcodes.ASTORE, 3);
    visitor.visitTypeInsn(Opcodes.NEW, "com/nginious/http/xsp/XspException");
    visitor.visitInsn(Opcodes.DUP);
    visitor.visitLdcInsn("Attribute set contains an invalid collection for tag " + getName() + " at "
            + getLocationDescriptor());
    visitor.visitVarInsn(Opcodes.ALOAD, 3);
    visitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "com/nginious/http/xsp/XspException", "<init>",
            "(Ljava/lang/String;Ljava/lang/Throwable;)V");
    visitor.visitInsn(Opcodes.ATHROW);

    visitor.visitMaxs(11, 11);
    visitor.visitEnd();
}

---

From source file:com.nginious.http.xsp.FormatDateTagPart.java

License:Apache License

/**
 * Creates bytecode for this format date tag part using the specified class writer and method visitor.
 * //from   www .  j  a va  2 s.  co m
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @param visitor the method visitor
 * @throws XspException if unable to create bytecode
 */
void compile(String intClassName, ClassWriter writer, MethodVisitor visitor) throws XspException {
    if (this.value == null) {
        throw new XspException(
                "Attribute value is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    if (this.pattern == null) {
        throw new XspException(
                "Attribute pattern is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    if (pattern.isExpression()) {
        throw new XspException("Expressions are not allowed in attribute pattern for tag + " + getName()
                + " at " + getLocationDescriptor());
    }

    if (this.var != null && var.isExpression()) {
        throw new XspException("Expressions are not allowed in attribute var for tag + " + getName() + " at "
                + getLocationDescriptor());
    }

    this.methodName = "formatDate" + methodNameCounter.getAndIncrement();
    visitor.visitVarInsn(Opcodes.ALOAD, 0);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitVarInsn(Opcodes.ALOAD, 2);
    visitor.visitVarInsn(Opcodes.ALOAD, 3);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, intClassName, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V");
}

---

From source file:com.nginious.http.xsp.FormatDateTagPart.java

License:Apache License

/**
 * Creates bytecode in a separate method for evaluating this format date tag part.
 * //w  w  w  .j  a v a 2s . c  o m
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @throws XspException if unable to create bytecode
 */
void compileMethod(String intClassName, ClassWriter writer) throws XspException {
    String[] exceptions = { "com/nginious/http/xsp/XspException" };
    MethodVisitor visitor = writer.visitMethod(Opcodes.ACC_PRIVATE, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V", null,
            exceptions);
    visitor.visitCode();

    Label tryLabel = new Label();
    Label startCatchLabel = new Label();

    // Start try block
    visitor.visitTryCatchBlock(tryLabel, startCatchLabel, startCatchLabel, "java/lang/Exception");

    visitor.visitLabel(tryLabel);

    visitor.visitTypeInsn(Opcodes.NEW, "java/text/SimpleDateFormat");
    visitor.visitInsn(Opcodes.DUP);
    pattern.compile(visitor, Type.STRING);
    visitor.visitVarInsn(Opcodes.ALOAD, 2);
    visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "com/nginious/http/HttpResponse", "getLocale",
            "()Ljava/util/Locale;");
    visitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/text/SimpleDateFormat", "<init>",
            "(Ljava/lang/String;Ljava/util/Locale;)V");
    visitor.visitVarInsn(Opcodes.ASTORE, 4);

    if (this.timeZone != null) {
        visitor.visitVarInsn(Opcodes.ALOAD, 4);
        String timeZoneDesc = timeZone.getStringContent();
        visitor.visitLdcInsn(timeZoneDesc);
        visitor.visitMethodInsn(Opcodes.INVOKESTATIC, "java/util/TimeZone", "getTimeZone",
                "(Ljava/lang/String;)Ljava/util/TimeZone;");
        visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/text/SimpleDateFormat", "setTimeZone",
                "(Ljava/util/TimeZone;)V");
    }

    try {
        String expression = value.getExpressionContent();
        ExpressionParser parser = new ExpressionParser();
        TreeExpression expr = parser.parse(expression);

        if (expr.getType() != Type.ANY) {
            throw new XspException("Expression in attribute value in tag " + getName()
                    + " is not an attribute or bean property " + " at line " + getLocationDescriptor());
        }

        expr.compile(visitor, Type.ANY);
        visitor.visitTypeInsn(Opcodes.CHECKCAST, "java/util/Date");
        visitor.visitVarInsn(Opcodes.ASTORE, 5);
    } catch (ExpressionException e) {
        throw new XspException("Invalid expression in attribute value in tag " + getName() + " at line "
                + getLocationDescriptor(), e);
    }

    Label nullLabel = new Label();
    visitor.visitVarInsn(Opcodes.ALOAD, 5);
    visitor.visitJumpInsn(Opcodes.IFNULL, nullLabel);

    visitor.visitVarInsn(Opcodes.ALOAD, 4);
    visitor.visitVarInsn(Opcodes.ALOAD, 5);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/text/SimpleDateFormat", "format",
            "(Ljava/util/Date;)Ljava/lang/String;");
    visitor.visitVarInsn(Opcodes.ASTORE, 5);

    if (this.var != null) {
        visitor.visitVarInsn(Opcodes.ALOAD, 1);
        var.compile(visitor, Type.STRING);
        visitor.visitVarInsn(Opcodes.ALOAD, 5);
        visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "com/nginious/http/HttpRequest", "setAttribute",
                "(Ljava/lang/String;Ljava/lang/Object;)V");
    } else {
        visitor.visitVarInsn(Opcodes.ALOAD, 3);
        visitor.visitVarInsn(Opcodes.ALOAD, 5);
        visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/StringBuffer", "append",
                "(Ljava/lang/String;)Ljava/lang/StringBuffer;");
        visitor.visitInsn(Opcodes.POP);
    }

    visitor.visitLabel(nullLabel);
    visitor.visitInsn(Opcodes.RETURN);

    visitor.visitLabel(startCatchLabel);

    visitor.visitVarInsn(Opcodes.ASTORE, 3);
    visitor.visitTypeInsn(Opcodes.NEW, "com/nginious/http/xsp/XspException");
    visitor.visitInsn(Opcodes.DUP);
    visitor.visitLdcInsn(
            "Attribute value contains an invalid date for tag " + getName() + " at " + getLocationDescriptor());
    visitor.visitVarInsn(Opcodes.ALOAD, 3);
    visitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "com/nginious/http/xsp/XspException", "<init>",
            "(Ljava/lang/String;Ljava/lang/Throwable;)V");
    visitor.visitInsn(Opcodes.ATHROW);

    visitor.visitMaxs(6, 6);
    visitor.visitEnd();

    super.compileMethod(intClassName, writer);
}

---

From source file:com.nginious.http.xsp.FormatNumberTagPart.java

License:Apache License

/**
 * Creates bytecode for this format number tag part using the specified class writer and method visitor. 
 * /* w  ww .  j  av  a  2  s .com*/
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @param visitor the method visitor
 * @throws XspException if unable to create bytecode
 */
void compile(String intClassName, ClassWriter writer, MethodVisitor visitor) throws XspException {
    if (this.value == null) {
        throw new XspException(
                "Attribute value is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    if (this.pattern == null) {
        throw new XspException(
                "Attribute pattern is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    if (pattern.isExpression()) {
        throw new XspException("Expressions are not allowed in attribute pattern for tag + " + getName()
                + " at " + getLocationDescriptor());
    }

    if (this.var != null && var.isExpression()) {
        throw new XspException("Expressions are not allowed in attribute var for tag + " + getName() + " at "
                + getLocationDescriptor());
    }

    this.methodName = "formatNumber" + methodNameCounter.getAndIncrement();
    visitor.visitVarInsn(Opcodes.ALOAD, 0);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitVarInsn(Opcodes.ALOAD, 2);
    visitor.visitVarInsn(Opcodes.ALOAD, 3);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, intClassName, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V");
}

---

From source file:com.nginious.http.xsp.FormatNumberTagPart.java

License:Apache License

/**
 * Creates bytecode in a separate method for evaluating this format number tag part.
 * // w ww .j a v  a 2  s .  c o  m
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @throws XspException if unable to create bytecode
 */
void compileMethod(String intClassName, ClassWriter writer) throws XspException {
    String[] exceptions = { "com/nginious/http/xsp/XspException" };
    MethodVisitor visitor = writer.visitMethod(Opcodes.ACC_PRIVATE, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V", null,
            exceptions);
    visitor.visitCode();

    Label tryLabel = new Label();
    Label startCatchLabel = new Label();

    // Start try block
    visitor.visitTryCatchBlock(tryLabel, startCatchLabel, startCatchLabel, "java/lang/Exception");

    visitor.visitLabel(tryLabel);

    visitor.visitTypeInsn(Opcodes.NEW, "java/text/DecimalFormat");
    visitor.visitInsn(Opcodes.DUP);
    pattern.compile(visitor, Type.STRING);
    visitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/text/DecimalFormat", "<init>",
            "(Ljava/lang/String;)V");
    visitor.visitVarInsn(Opcodes.ASTORE, 4);

    ExpressionParser parser = null;
    TreeExpression expr = null;

    try {
        String expression = value.getExpressionContent();
        parser = new ExpressionParser();
        expr = parser.parse(expression);

        if (expr.getType() != Type.ANY) {
            throw new XspException("Expression in attribute value in tag " + getName()
                    + " is not an attribute or bean property " + " at line " + getLocationDescriptor());
        }
    } catch (ExpressionException e) {
        throw new XspException("Invalid expression in attribute value in tag " + getName() + " at line "
                + getLocationDescriptor(), e);
    }

    visitor.visitVarInsn(Opcodes.ALOAD, 4);
    expr.compile(visitor, Type.DOUBLE);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/text/DecimalFormat", "format",
            "(D)Ljava/lang/String;");
    visitor.visitVarInsn(Opcodes.ASTORE, 5);

    if (this.var != null) {
        visitor.visitVarInsn(Opcodes.ALOAD, 1);
        var.compile(visitor, Type.STRING);
        visitor.visitVarInsn(Opcodes.ALOAD, 5);
        visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "com/nginious/http/HttpRequest", "setAttribute",
                "(Ljava/lang/String;Ljava/lang/Object;)V");
    } else {
        visitor.visitVarInsn(Opcodes.ALOAD, 3);
        visitor.visitVarInsn(Opcodes.ALOAD, 5);
        visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/StringBuffer", "append",
                "(Ljava/lang/String;)Ljava/lang/StringBuffer;");
        visitor.visitInsn(Opcodes.POP);
    }

    visitor.visitInsn(Opcodes.RETURN);

    visitor.visitLabel(startCatchLabel);

    visitor.visitVarInsn(Opcodes.ASTORE, 4);
    visitor.visitTypeInsn(Opcodes.NEW, "com/nginious/http/xsp/XspException");
    visitor.visitInsn(Opcodes.DUP);
    visitor.visitLdcInsn("Attribute value contains an invalid number for tag " + getName() + " at "
            + getLocationDescriptor());
    visitor.visitVarInsn(Opcodes.ALOAD, 4);
    visitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "com/nginious/http/xsp/XspException", "<init>",
            "(Ljava/lang/String;Ljava/lang/Throwable;)V");
    visitor.visitInsn(Opcodes.ATHROW);

    visitor.visitMaxs(6, 6);
    visitor.visitEnd();

    super.compileMethod(intClassName, writer);
}

---

From source file:com.nginious.http.xsp.IfTagPart.java

License:Apache License

/**
 * Creates bytecode for this if tag part using the specified  class writer and method visitor. A separate
 * method is created within the class to evaluate the expression in the test attribute.
 * //from   w  ww .  jav a 2  s .  c o  m
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @param visitor the method visitor
 * @throws XspException if unable to create bytecode
 */
void compile(String intClassName, ClassWriter writer, MethodVisitor visitor) throws XspException {
    if (this.part == null) {
        throw new XspException(
                "Attribute test is missing for tag " + getName() + " at " + getLocationDescriptor());
    }

    this.methodName = "ifTest" + methodNameCounter.getAndIncrement();
    visitor.visitVarInsn(Opcodes.ALOAD, 0);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, intClassName, this.methodName, "()Z");
    Label falseLabel = new Label();
    visitor.visitJumpInsn(Opcodes.IFEQ, falseLabel);

    for (XspPart part : this.contentParts) {
        part.compile(intClassName, writer, visitor);
    }

    visitor.visitLabel(falseLabel);
}

---

From source file:com.nginious.http.xsp.MessageTagPart.java

License:Apache License

/**
 * Creates bytecode for this message tag part using the specified class writer and method visitor.
 * /*  w  w w.j a  v  a  2s .  c o  m*/
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @param visitor the method visitor
 * @throws XspException if unable to create bytecode
 */
void compile(String intClassName, ClassWriter writer, MethodVisitor visitor) throws XspException {
    if (this.key == null) {
        throw new XspException(
                "Attribute key is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    if (this.bundle == null) {
        throw new XspException(
                "Attribute bundle is missing for tag + " + getName() + " at " + getLocationDescriptor());
    }

    if (this.var != null && var.isExpression()) {
        throw new XspException("Expressions are not allowed in attribute var for tag + " + getName() + " at "
                + getLocationDescriptor());
    }

    this.methodName = "message" + methodNameCounter.getAndIncrement();
    visitor.visitVarInsn(Opcodes.ALOAD, 0);
    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitVarInsn(Opcodes.ALOAD, 2);
    visitor.visitVarInsn(Opcodes.ALOAD, 3);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, intClassName, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V");
}

---

From source file:com.nginious.http.xsp.MessageTagPart.java

License:Apache License

/**
 * Creates bytecode in a separate method for evaluating this message tag part.
 * /*from   w w w.ja  v a2 s.c  o m*/
 * @param intClassName the binary class name of the class being created
 * @param writer the class writer
 * @throws XspException if unable to create bytecode
 */
void compileMethod(String intClassName, ClassWriter writer) throws XspException {
    MethodVisitor visitor = writer.visitMethod(Opcodes.ACC_PRIVATE, this.methodName,
            "(Lcom/nginious/http/HttpRequest;Lcom/nginious/http/HttpResponse;Ljava/lang/StringBuffer;)V", null,
            null);
    visitor.visitCode();

    if (this.var != null) {
        visitor.visitVarInsn(Opcodes.ALOAD, 1);
        var.compile(visitor, Type.STRING);
    } else {
        visitor.visitVarInsn(Opcodes.ALOAD, 3);
    }

    bundle.compile(visitor, Type.STRING);
    visitor.visitVarInsn(Opcodes.ALOAD, 2);
    visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "com/nginious/http/HttpResponse", "getLocale",
            "()Ljava/util/Locale;");
    visitor.visitMethodInsn(Opcodes.INVOKESTATIC, "java/util/ResourceBundle", "getBundle",
            "(Ljava/lang/String;Ljava/util/Locale;)Ljava/util/ResourceBundle;");

    key.compile(visitor, Type.STRING);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/util/ResourceBundle", "getString",
            "(Ljava/lang/String;)Ljava/lang/String;");

    if (this.args != null) {
        try {
            String expression = args.getExpressionContent();
            ExpressionParser parser = new ExpressionParser();
            TreeExpression expr = parser.parse(expression);

            if (expr.getType() != Type.ANY) {
                throw new XspException("Expression in attribute value in args " + getName()
                        + " is not an attribute or bean property " + " at line " + getLocationDescriptor());
            }

            expr.compile(visitor, Type.ANY);
            visitor.visitTypeInsn(Opcodes.CHECKCAST, "[Ljava/lang/Object;");
            visitor.visitMethodInsn(Opcodes.INVOKESTATIC, "java/text/MessageFormat", "format",
                    "(Ljava/lang/String;[Ljava/lang/Object;)Ljava/lang/String;");
        } catch (ExpressionException e) {
            throw new XspException("Invalid expression in attribute value in tag " + getName() + " at line "
                    + getLocationDescriptor(), e);
        }
    }

    if (this.var != null) {
        visitor.visitMethodInsn(Opcodes.INVOKEINTERFACE, "com/nginious/http/HttpRequest", "setAttribute",
                "(Ljava/lang/String;Ljava/lang/Object;)V");
    } else {
        visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/StringBuffer", "append",
                "(Ljava/lang/String;)Ljava/lang/StringBuffer;");
        visitor.visitInsn(Opcodes.POP);
    }

    visitor.visitInsn(Opcodes.RETURN);
    visitor.visitMaxs(5, 5);
    visitor.visitEnd();

    super.compileMethod(intClassName, writer);
}

---

• «
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• 49
• 50
• »