Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.lang.reflect.Field;
import java.util.HashMap;
import android.util.Log;

public class Main {
    private static final HashMap<String, Field> fieldCache = new HashMap<String, Field>();

    public static Object getObjectField(Object obj, String fieldName) {
        try {
            return findField(obj.getClass(), fieldName).get(obj);
        } catch (IllegalAccessException e) {
            // should not happen
            Log.v("test", e.getMessage());
            throw new IllegalAccessError(e.getMessage());
        } catch (IllegalArgumentException e) {
            throw e;
        }
    }

    /**
     * Look up a field in a class and set it to accessible. The result is cached.
     * If the field was not found, a {@link NoSuchFieldError} will be thrown.
     */
    public static Field findField(Class<?> clazz, String fieldName) {
        StringBuilder sb = new StringBuilder(clazz.getName());
        sb.append('#');
        sb.append(fieldName);
        String fullFieldName = sb.toString();

        if (fieldCache.containsKey(fullFieldName)) {
            Field field = fieldCache.get(fullFieldName);
            if (field == null)
                throw new NoSuchFieldError(fullFieldName);
            return field;
        }

        try {
            Field field = findFieldRecursiveImpl(clazz, fieldName);
            field.setAccessible(true);
            fieldCache.put(fullFieldName, field);
            return field;
        } catch (NoSuchFieldException e) {
            fieldCache.put(fullFieldName, null);
            throw new NoSuchFieldError(fullFieldName);
        }
    }

    private static Field findFieldRecursiveImpl(Class<?> clazz, String fieldName) throws NoSuchFieldException {
        try {
            return clazz.getDeclaredField(fieldName);
        } catch (NoSuchFieldException e) {
            while (true) {
                clazz = clazz.getSuperclass();
                if (clazz == null || clazz.equals(Object.class))
                    break;

                try {
                    return clazz.getDeclaredField(fieldName);
                } catch (NoSuchFieldException ignored) {
                }
            }
            throw e;
        }
    }
}