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Struts example source code file (JavacErrorDetail.java)

This example Struts source code file (JavacErrorDetail.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Struts tags/keywords

arraylist, bufferedreader, fileinputstream, inputstreamreader, io, ioexception, ioexception, javacerrordetail, javacerrordetail, jspcompilationcontext, list, string, string, stringbuffer, stringbuffer, util

The Struts JavacErrorDetail.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.struts2.jasper.compiler;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.struts2.jasper.JspCompilationContext;

/**
 * Class providing details about a javac compilation error.
 *
 * @author Jan Luehe
 * @author Kin-man Chung
 */
public class JavacErrorDetail {

    private String javaFileName;
    private int javaLineNum;
    private String jspFileName;
    private int jspBeginLineNum;
    private StringBuffer errMsg;
    private String jspExtract = null;

    /**
     * Constructor.
     *
     * @param javaFileName The name of the Java file in which the 
     * compilation error occurred
     * @param javaLineNum The compilation error line number
     * @param errMsg The compilation error message
     */
    public JavacErrorDetail(String javaFileName,
                            int javaLineNum,
                            StringBuffer errMsg) {

        this.javaFileName = javaFileName;
        this.javaLineNum = javaLineNum;
        this.errMsg = errMsg;
        this.jspBeginLineNum = -1;
    }

    /**
     * Constructor.
     *
     * @param javaFileName The name of the Java file in which the 
     * compilation error occurred
     * @param javaLineNum The compilation error line number
     * @param jspFileName The name of the JSP file from which the Java source
     * file was generated
     * @param jspBeginLineNum The start line number of the JSP element
     * responsible for the compilation error
     * @param errMsg The compilation error message
     */
    public JavacErrorDetail(String javaFileName,
                            int javaLineNum,
                            String jspFileName,
                            int jspBeginLineNum,
                            StringBuffer errMsg) {

        this(javaFileName, javaLineNum, jspFileName, jspBeginLineNum, errMsg,
                null);
    }

    public JavacErrorDetail(String javaFileName,
            int javaLineNum,
            String jspFileName,
            int jspBeginLineNum,
            StringBuffer errMsg,
            JspCompilationContext ctxt) {
        
        this(javaFileName, javaLineNum, errMsg);
        this.jspFileName = jspFileName;
        this.jspBeginLineNum = jspBeginLineNum;
        
        if (jspBeginLineNum > 0 && ctxt != null) {
            InputStream is = null;
            FileInputStream  fis = null;
            
            try {
                // Read both files in, so we can inspect them
                is = ctxt.getResourceAsStream(jspFileName);
                String[] jspLines = readFile(is);
    
                fis = new FileInputStream(ctxt.getServletJavaFileName());
                String[] javaLines = readFile(fis);
    
                // If the line contains the opening of a multi-line scriptlet
                // block, then the JSP line number we got back is probably
                // faulty.  Scan forward to match the java line...
                if (jspLines[jspBeginLineNum-1].lastIndexOf("<%") >
                    jspLines[jspBeginLineNum-1].lastIndexOf("%>")) {
                    String javaLine = javaLines[javaLineNum-1].trim();
    
                    for (int i=jspBeginLineNum-1; i<jspLines.length; i++) {
                        if (jspLines[i].indexOf(javaLine) != -1) {
                            // Update jsp line number
                            this.jspBeginLineNum = i+1;
                            break;
                        }
                    }
                }
    
                // copy out a fragment of JSP to display to the user
                StringBuffer fragment = new StringBuffer(1024);
                int startIndex = Math.max(0, this.jspBeginLineNum-1-3);
                int endIndex = Math.min(
                        jspLines.length-1, this.jspBeginLineNum-1+3);
    
                for (int i=startIndex;i<=endIndex; ++i) {
                    fragment.append(i+1);
                    fragment.append(": ");
                    fragment.append(jspLines[i]);
                    fragment.append("\n");
                }
                jspExtract = fragment.toString();
    
            } catch (IOException ioe) {
                // Can't read files - ignore
            } finally {
                if (is != null) {
                    try {
                        is.close();
                    } catch (IOException ioe) {
                        // Ignore
                    }
                }
                if (fis != null) {
                    try {
                        fis.close();
                    } catch (IOException ioe) {
                        // Ignore
                    }
                }
            }
        }
    }

    /**
     * Gets the name of the Java source file in which the compilation error
     * occurred.
     *
     * @return Java source file name
     */
    public String getJavaFileName() {
        return this.javaFileName;
    }

    /**
     * Gets the compilation error line number.
     * 
     * @return Compilation error line number
     */
    public int getJavaLineNumber() {
        return this.javaLineNum;
    }

    /**
     * Gets the name of the JSP file from which the Java source file was
     * generated.
     *
     * @return JSP file from which the Java source file was generated.
     */
    public String getJspFileName() {
        return this.jspFileName;
    }

    /**
     * Gets the start line number (in the JSP file) of the JSP element
     * responsible for the compilation error.
     *
     * @return Start line number of the JSP element responsible for the
     * compilation error
     */
    public int getJspBeginLineNumber() {
        return this.jspBeginLineNum;
    }

    /**
     * Gets the compilation error message.
     *
     * @return Compilation error message
     */
    public String getErrorMessage() {
        return this.errMsg.toString();
    }
    
    /**
     * Gets the extract of the JSP that corresponds to this message.
     *
     * @return Extract of JSP where error occurred
     */
    public String getJspExtract() {
        return this.jspExtract;
    }
    
    /**
     * Reads a text file from an input stream into a String[]. Used to read in
     * the JSP and generated Java file when generating error messages.
     */
    private String[] readFile(InputStream s) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(s));
        List lines = new ArrayList();
        String line;

        while ( (line = reader.readLine()) != null ) {
            lines.add(line);
        }

        return (String[]) lines.toArray( new String[lines.size()] );
    }
}

Other Struts examples (source code examples)

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