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 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
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 * GPL Classpath Exception:
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package org.apache.jasper.compiler;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.io.UnsupportedEncodingException;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.logging.Logger;
import java.util.logging.Level;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;

import org.eclipse.jdt.core.compiler.IProblem;
import org.eclipse.jdt.internal.compiler.ClassFile;
import org.eclipse.jdt.internal.compiler.CompilationResult;
import org.eclipse.jdt.internal.compiler.Compiler;
import org.eclipse.jdt.internal.compiler.DefaultErrorHandlingPolicies;
import org.eclipse.jdt.internal.compiler.ICompilerRequestor;
import org.eclipse.jdt.internal.compiler.IErrorHandlingPolicy;
import org.eclipse.jdt.internal.compiler.IProblemFactory;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileReader;
import org.eclipse.jdt.internal.compiler.env.ICompilationUnit;
import org.eclipse.jdt.internal.compiler.env.INameEnvironment;
import org.eclipse.jdt.internal.compiler.env.NameEnvironmentAnswer;
import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
import org.eclipse.jdt.internal.compiler.problem.DefaultProblemFactory;

/**
 * JDT class compiler. This compiler will load source dependencies from the
 * context classloader, reducing dramatically disk access during 
 * the compilation process.
 *
 * @author Cocoon2
 * @author Remy Maucherat
 * @author Kin-man Chung   Modified to implement JavaCompiler
 */

public class JDTJavaCompiler implements JavaCompiler {

    private final Map settings = new HashMap();
    private JspCompilationContext ctxt;
    private ErrorDispatcher errDispatcher;
    private Logger log;
    private String javaFileName;


    public void init(JspCompilationContext ctxt,
                     ErrorDispatcher errDispatcher,
                     boolean suppressLogging) {
        this.errDispatcher = errDispatcher;
        this.ctxt = ctxt;
        log = Logger.getLogger(JDTJavaCompiler.class.getName());
        if (suppressLogging) {
            log.setLevel(Level.OFF);
        }
    }

    public void release() {
    }

    public void setExtdirs(String exts) {
        // no op here
    }

    public void setClassPath(List<File> cpath) {
       // No op here, because the current classloader is used.  However,
       // This may not include the system classpath specified in options
    }

    public long getClassLastModified() {
        File classFile = new File(ctxt.getClassFileName());
        return classFile.lastModified();
    }

    public Writer getJavaWriter(String javaFileName,
                                String javaEncoding)
            throws JasperException {

        this.javaFileName = javaFileName;

        Writer writer = null;
        try {
            writer = new OutputStreamWriter(
                        new FileOutputStream(javaFileName), javaEncoding);
        } catch (UnsupportedEncodingException ex) {
            errDispatcher.jspError("jsp.error.needAlternateJavaEncoding",
                                   javaEncoding);
        } catch (IOException ex) {
            errDispatcher.jspError("jsp.error.unableToCreateOutputWriter",
                                   javaFileName, ex);
        }
        return writer;
    }

    public void setDebug(boolean debug) {
        settings.put(CompilerOptions.OPTION_LineNumberAttribute,
                     CompilerOptions.GENERATE);
        settings.put(CompilerOptions.OPTION_SourceFileAttribute,
                     CompilerOptions.GENERATE);
        settings.put(CompilerOptions.OPTION_ReportDeprecation,
                     CompilerOptions.IGNORE);
        if (debug) {
            settings.put(CompilerOptions.OPTION_LocalVariableAttribute,
                         CompilerOptions.GENERATE);
        }
    }

    public void setSourceVM(String sourceVM) {
        if(sourceVM.equals("1.1")) {
            settings.put(CompilerOptions.OPTION_Source,
                         CompilerOptions.VERSION_1_1);
        } else if(sourceVM.equals("1.2")) {
            settings.put(CompilerOptions.OPTION_Source,
                         CompilerOptions.VERSION_1_2);
        } else if(sourceVM.equals("1.3")) {
            settings.put(CompilerOptions.OPTION_Source,
                         CompilerOptions.VERSION_1_3);
        } else if(sourceVM.equals("1.4")) {
            settings.put(CompilerOptions.OPTION_Source,
                         CompilerOptions.VERSION_1_4);
        } else if(sourceVM.equals("1.5")) {
            settings.put(CompilerOptions.OPTION_Source,
                         CompilerOptions.VERSION_1_5);
        } else if(sourceVM.equals("1.6")) {
            settings.put(CompilerOptions.OPTION_Source,
                         CompilerOptions.VERSION_1_6);
        } else if(sourceVM.equals("1.7")) {
            settings.put(CompilerOptions.OPTION_Source,
                         CompilerOptions.VERSION_1_7);
        } else {
            log.warning("Unknown source VM " + sourceVM + " ignored.");
            settings.put(CompilerOptions.OPTION_Source,
                    CompilerOptions.VERSION_1_5);
        }
    }

    public void setTargetVM(String targetVM) {
        if(targetVM.equals("1.1")) {
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                         CompilerOptions.VERSION_1_1);
        } else if(targetVM.equals("1.2")) {
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                         CompilerOptions.VERSION_1_2);
        } else if(targetVM.equals("1.3")) {
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                         CompilerOptions.VERSION_1_3);
        } else if(targetVM.equals("1.4")) {
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                         CompilerOptions.VERSION_1_4);
        } else if(targetVM.equals("1.5")) {
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                         CompilerOptions.VERSION_1_5);
        } else if(targetVM.equals("1.6")) {
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                         CompilerOptions.VERSION_1_6);
        } else if(targetVM.equals("1.7")) {
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                         CompilerOptions.VERSION_1_7);
        } else {
            log.warning("Unknown target VM " + targetVM + " ignored.");
            settings.put(CompilerOptions.OPTION_TargetPlatform,
                    CompilerOptions.VERSION_1_5);
        }
    }

    public void saveClassFile(String className, String classFileName) {
        // class file are alwyas saved.
    }

    public void doJavaFile(boolean keep) {
        if (!keep) {
            File javaFile = new File(javaFileName);
            javaFile.delete();
        }
    }

    public JavacErrorDetail[] compile(final String targetClassName,
                                      final Node.Nodes pageNodes)
            throws JasperException {

        final String sourceFile = ctxt.getServletJavaFileName();
        final String outputDir =
            ctxt.getOptions().getScratchDir().getAbsolutePath();
        String packageName = ctxt.getServletPackageName();

        final ClassLoader classLoader = ctxt.getJspLoader();
        String[] fileNames = new String[] {sourceFile};
        String[] classNames = new String[] {targetClassName};
        final ArrayList<JavacErrorDetail> problemList =
                new ArrayList<JavacErrorDetail>();

        class CompilationUnit implements ICompilationUnit {

            String className;
            String sourceFile;

            CompilationUnit(String sourceFile, String className) {
                this.className = className;
                this.sourceFile = sourceFile;
            }

            public char[] getFileName() {
                return className.toCharArray();
            }
            
            public char[] getContents() {
                char[] result = null;
                Reader reader = null;
                try {
                    InputStreamReader isReader =
                        new InputStreamReader(new FileInputStream(sourceFile),
                                ctxt.getOptions().getJavaEncoding());
                    reader = new BufferedReader(isReader);
                    if (reader != null) {
                        char[] chars = new char[8192];
                        StringBuilder buf = new StringBuilder();
                        int count;
                        while ((count = reader.read(chars, 0, 
                                                    chars.length)) > 0) {
                            buf.append(chars, 0, count);
                        }
                        result = new char[buf.length()];
                        buf.getChars(0, result.length, result, 0);
                    }
                } catch (IOException e) {
                    log.log(Level.SEVERE, "Compilation error", e);
                } finally {
                    if (reader != null) {
                        try {
                            reader.close();
                        } catch (IOException ioe) {
                            // Ignore
                        }
                    }
                }
                return result;
            }
            
            public char[] getMainTypeName() {
                int dot = className.lastIndexOf('.');
                if (dot > 0) {
                    return className.substring(dot + 1).toCharArray();
                }
                return className.toCharArray();
            }
            
            public char[][] getPackageName() {
                StringTokenizer izer = 
                    new StringTokenizer(className, ".");
                char[][] result = new char[izer.countTokens()-1][];
                for (int i = 0; i < result.length; i++) {
                    String tok = izer.nextToken();
                    result[i] = tok.toCharArray();
                }
                return result;
            }

            public boolean ignoreOptionalProblems() {
                return false;
            }
        }

        final INameEnvironment env = new INameEnvironment() {

                public NameEnvironmentAnswer 
                    findType(char[][] compoundTypeName) {
                    String result = "";
                    String sep = "";
                    for (int i = 0; i < compoundTypeName.length; i++) {
                        result += sep;
                        result += new String(compoundTypeName[i]);
                        sep = ".";
                    }
                    return findType(result);
                }

                public NameEnvironmentAnswer 
                    findType(char[] typeName, 
                             char[][] packageName) {
                        String result = "";
                        String sep = "";
                        for (int i = 0; i < packageName.length; i++) {
                            result += sep;
                            result += new String(packageName[i]);
                            sep = ".";
                        }
                        result += sep;
                        result += new String(typeName);
                        return findType(result);
                }
                
                private NameEnvironmentAnswer findType(String className) {

                    InputStream is = null;
                    try {
                        if (className.equals(targetClassName)) {
                            ICompilationUnit compilationUnit = 
                                new CompilationUnit(sourceFile, className);
                            return 
                                new NameEnvironmentAnswer(compilationUnit, null);
                        }
                        String resourceName = 
                            className.replace('.', '/') + ".class";
                        is = classLoader.getResourceAsStream(resourceName);
                        if (is != null) {
                            byte[] classBytes;
                            byte[] buf = new byte[8192];
                            ByteArrayOutputStream baos = 
                                new ByteArrayOutputStream(buf.length);
                            int count;
                            while ((count = is.read(buf, 0, buf.length)) > 0) {
                                baos.write(buf, 0, count);
                            }
                            baos.flush();
                            classBytes = baos.toByteArray();
                            char[] fileName = className.toCharArray();
                            ClassFileReader classFileReader = 
                                new ClassFileReader(classBytes, fileName, 
                                                    true);
                            return 
                                new NameEnvironmentAnswer(classFileReader, null);
                        }
                    } catch (IOException exc) {
                        log.log(Level.SEVERE, "Compilation error", exc);
                    } catch (org.eclipse.jdt.internal.compiler.classfmt.ClassFormatException exc) {
                        log.log(Level.SEVERE, "Compilation error", exc);
                    } finally {
                        if (is != null) {
                            try {
                                is.close();
                            } catch (IOException exc) {
                                // Ignore
                            }
                        }
                    }
                    return null;
                }

                private boolean isPackage(String result) {
                    if (result.equals(targetClassName)) {
                        return false;
                    }
                    String resourceName = result.replace('.', '/') + ".class";
                    InputStream is = 
                        classLoader.getResourceAsStream(resourceName);
                    return is == null;
                }

                public boolean isPackage(char[][] parentPackageName, 
                                         char[] packageName) {
                    String result = "";
                    String sep = "";
                    if (parentPackageName != null) {
                        for (int i = 0; i < parentPackageName.length; i++) {
                            result += sep;
                            String str = new String(parentPackageName[i]);
                            result += str;
                            sep = ".";
                        }
                    }
                    String str = new String(packageName);
                    if (Character.isUpperCase(str.charAt(0))) {
                        if (!isPackage(result)) {
                            return false;
                        }
                    }
                    result += sep;
                    result += str;
                    return isPackage(result);
                }

                public void cleanup() {
                }

            };

        final IErrorHandlingPolicy policy = 
            DefaultErrorHandlingPolicies.proceedWithAllProblems();

        if (ctxt.getOptions().getJavaEncoding() != null) {
            settings.put(CompilerOptions.OPTION_Encoding,
                    ctxt.getOptions().getJavaEncoding());
        }

        final IProblemFactory problemFactory = 
            new DefaultProblemFactory(Locale.getDefault());
        
        final ICompilerRequestor requestor = new ICompilerRequestor() {
                public void acceptResult(CompilationResult result) {
                    try {
                        if (result.hasProblems()) {
                            IProblem[] problems = safeGetProblems(result);
                            for (int i = 0; i < problems.length; i++) {
                                IProblem problem = problems[i];
                                if (problem.isError()) {
                                    String name = 
                                        new String(problems[i].getOriginatingFileName());
                                    try {
                                        problemList.add(
                                            ErrorDispatcher.createJavacError(
                                                name,
                                                pageNodes,
                                                new StringBuilder(problem.getMessage()), 
                                                problem.getSourceLineNumber()));
                                    } catch (JasperException e) {
                                        log.log(Level.SEVERE, "Error visiting node", e);
                                    }
                                }
                            }
                        }
                        if (problemList.isEmpty()) {
                            ClassFile[] classFiles = result.getClassFiles();
                            for (int i = 0; i < classFiles.length; i++) {
                                ClassFile classFile = classFiles[i];
                                char[][] compoundName = 
                                    classFile.getCompoundName();
                                String className = "";
                                String sep = "";
                                for (int j = 0; 
                                     j < compoundName.length; j++) {
                                    className += sep;
                                    className += new String(compoundName[j]);
                                    sep = ".";
                                }
                                byte[] bytes = classFile.getBytes();
                                String outFile = outputDir + "/" + 
                                    className.replace('.', '/') + ".class";
                                FileOutputStream fout = 
                                    new FileOutputStream(outFile);
                                BufferedOutputStream bos = 
                                    new BufferedOutputStream(fout);
                                bos.write(bytes);
                                bos.close();
                            }
                        }
                    } catch (IOException exc) {
                        log.log(Level.SEVERE, "Compilation error", exc);
                    }
                }
            };

        ICompilationUnit[] compilationUnits = 
            new ICompilationUnit[classNames.length];
        for (int i = 0; i < compilationUnits.length; i++) {
            compilationUnits[i] = new CompilationUnit(fileNames[i], classNames[i]);
        }

        Compiler compiler = new Compiler(env,
                                         policy,
                                         settings,
                                         requestor,
                                         problemFactory);
        compiler.compile(compilationUnits);

        if (problemList.isEmpty()) {
            return null;
        }
        return problemList.toArray(new JavacErrorDetail[]{});
    }
    
    private static boolean USE_INTROSPECTION_TO_INVOKE_GET_PROBLEM = false;
    private static java.lang.reflect.Method GET_PROBLEM_METH = null;
    /**
     * Invoke CompilationResult#getProblems safely so that it works with
     * 3.1.1 and more recent versions of the eclipse java compiler.
     * See https://jsp.dev.java.net/issues/show_bug.cgi?id=13
     * 
     * @param result The compilation result.
     * @return The same object than CompilationResult#getProblems
     */
    private static final IProblem[] safeGetProblems(CompilationResult result) {
        if (!USE_INTROSPECTION_TO_INVOKE_GET_PROBLEM) {
            try {
                return result.getProblems();
            } catch (NoSuchMethodError re) {
                USE_INTROSPECTION_TO_INVOKE_GET_PROBLEM = true;
            }
        }
        try {
            if (GET_PROBLEM_METH == null) {
                GET_PROBLEM_METH = result.getClass()
                        .getDeclaredMethod("getProblems", new Class[] {});
            }
            //an array of a particular type can be casted into an array of a super type.
            return (IProblem[]) GET_PROBLEM_METH.invoke(result, null);
        } catch (Throwable e) {
            if (e instanceof RuntimeException) {
                throw (RuntimeException)e;
            } else {
                throw new RuntimeException(e);
            }
        }
    }
}