Update Clob data stored in MySql from a Servlet
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class UpdateMySqlClobServlet extends HttpServlet {
public static Connection getConnection() throws Exception {
String driver = "org.gjt.mm.mysql.Driver";
String url = "jdbc:mysql://localhost/databaseName";
String username = "root";
String password = "root";
Class.forName(driver);
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException,
ServletException {
Connection conn = null;
String id = "001";
String fileAsURL = "http://yourwebsite/fileName.dat";
ServletOutputStream out = response.getOutputStream();
response.setContentType("text/html");
out.println("<html><head><title>UpdateMySqlClobServlet</title></head>");
try {
conn = getConnection();
String fileContent = getClobsContentAsString(fileAsURL);
updateCLOB(conn, id, fileContent);
out.println("<body><h4>OK: updated an existing record with id=" + id + "</h4></body></html>");
} catch (Exception e) {
e.printStackTrace();
out.println("<body><h4>Error: " + e.getMessage() + "</h4></body></html>");
}
}
public void updateCLOB(Connection conn, String id, String fileContent) throws Exception {
PreparedStatement pstmt = null;
try {
pstmt = conn.prepareStatement("update dataTable set filebody= ? where id = ?");
pstmt.setString(1, fileContent);
pstmt.setString(2, id);
pstmt.executeUpdate();
} finally {
pstmt.close();
}
}
public static String getClobsContentAsString(String urlAsString) throws Exception {
InputStream content = null;
try {
java.net.URL url = new java.net.URL(urlAsString);
java.net.URLConnection urlConn = url.openConnection();
urlConn.connect();
content = urlConn.getInputStream();
int BUFFER_SIZE = 1024;
ByteArrayOutputStream output = new ByteArrayOutputStream();
int length;
byte[] buffer = new byte[BUFFER_SIZE];
while ((length = content.read(buffer)) != -1) {
output.write(buffer, 0, length);
}
return new String(output.toByteArray());
} finally {
content.close();
}
}
}
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