org.eclipse.jetty.ee8.nested.ResponseWriter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jetty-ee8-nested Show documentation
The jetty core handler adapted to legacy ee8 handler.
The newest version!
//
// ========================================================================
// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.ee8.nested;

import java.io.IOException;
import java.io.InterruptedIOException;
import java.io.PrintWriter;
import java.util.Formatter;
import java.util.Locale;
import javax.servlet.ServletResponse;
import org.eclipse.jetty.io.EofException;
import org.eclipse.jetty.io.RuntimeIOException;
import org.eclipse.jetty.io.WriteThroughWriter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Specialized PrintWriter for servlet Responses
 * An instance of ResponseWriter is the {@link PrintWriter} subclass returned by {@link Response#getWriter()}.
 * It differs from the standard {@link PrintWriter} in that:

 * It does not support autoflush
 * The default Locale for {@link #format(String, Object...)} is the locale obtained by {@link ServletResponse#getLocale()}
 * If a write or print method is called while {@link #checkError()}  returns true, then a {@link RuntimeIOException} is thrown to stop needless iterations.
 * The writer may be reopen to allow for recycling
 * 
 */
public class ResponseWriter extends PrintWriter {

    private static final Logger LOG = LoggerFactory.getLogger(ResponseWriter.class);

    private final WriteThroughWriter _writer;

    private final Locale _locale;

    private final String _encoding;

    private IOException _ioException;

    private boolean _isClosed = false;

    private Formatter _formatter;

    public ResponseWriter(WriteThroughWriter httpWriter, Locale locale, String encoding) {
        super(httpWriter, false);
        _writer = httpWriter;
        _locale = locale;
        _encoding = encoding;
    }

    public boolean isFor(Locale locale, String encoding) {
        if (_locale == null && locale != null)
            return false;
        if (_encoding == null && encoding != null)
            return false;
        return _encoding.equalsIgnoreCase(encoding) && _locale.equals(locale);
    }

    protected void reopen() {
        synchronized (lock) {
            _isClosed = false;
            clearError();
            out = _writer;
        }
    }

    @Override
    protected void clearError() {
        synchronized (lock) {
            _ioException = null;
            super.clearError();
        }
    }

    @Override
    public boolean checkError() {
        synchronized (lock) {
            return _ioException != null || super.checkError();
        }
    }

    private void setError(Throwable th) {
        super.setError();
        if (th instanceof IOException)
            _ioException = (IOException) th;
        else {
            _ioException = new IOException(String.valueOf(th));
            _ioException.initCause(th);
        }
        if (LOG.isDebugEnabled())
            LOG.debug("PrintWriter Error is set", th);
    }

    @Override
    protected void setError() {
        setError(new IOException());
    }

    /**
     * Check to make sure that the stream has not been closed
     */
    private void isOpen() throws IOException {
        if (_ioException != null)
            throw _ioException;
        if (_isClosed) {
            _ioException = new EofException("Stream closed");
            throw _ioException;
        }
    }

    @Override
    public void flush() {
        try {
            synchronized (lock) {
                isOpen();
                out.flush();
            }
        } catch (Throwable ex) {
            setError(ex);
        }
    }

    @Override
    public void close() {
        try {
            synchronized (lock) {
                out.close();
                _isClosed = true;
            }
        } catch (IOException ex) {
            setError(ex);
        }
    }

    /**
     * Used to mark this writer as closed during any asynchronous completion operation.
     */
    public void markAsClosed() {
        synchronized (lock) {
            _isClosed = true;
        }
    }

    @Override
    public void write(int c) {
        try {
            synchronized (lock) {
                isOpen();
                out.write(c);
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("Write interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
    }

    @Override
    public void write(char[] buf, int off, int len) {
        try {
            synchronized (lock) {
                isOpen();
                out.write(buf, off, len);
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("Write interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
    }

    @Override
    public void write(char[] buf) {
        this.write(buf, 0, buf.length);
    }

    @Override
    public void write(String s, int off, int len) {
        try {
            synchronized (lock) {
                isOpen();
                out.write(s, off, len);
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("Write interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
    }

    @Override
    public void write(String s) {
        this.write(s, 0, s.length());
    }

    @Override
    public void print(boolean b) {
        this.write(b ? "true" : "false");
    }

    @Override
    public void print(char c) {
        this.write(c);
    }

    @Override
    public void print(int i) {
        this.write(String.valueOf(i));
    }

    @Override
    public void print(long l) {
        this.write(String.valueOf(l));
    }

    @Override
    public void print(float f) {
        this.write(String.valueOf(f));
    }

    @Override
    public void print(double d) {
        this.write(String.valueOf(d));
    }

    @Override
    public void print(char[] s) {
        this.write(s);
    }

    @Override
    public void print(String s) {
        if (s == null)
            s = "null";
        this.write(s);
    }

    @Override
    public void print(Object obj) {
        this.write(String.valueOf(obj));
    }

    @Override
    public void println() {
        try {
            synchronized (lock) {
                isOpen();
                out.write(System.lineSeparator());
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("write interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
    }

    @Override
    public void println(boolean b) {
        println(Boolean.toString(b));
    }

    @Override
    public void println(char c) {
        try {
            synchronized (lock) {
                isOpen();
                out.write(c);
                out.write(System.lineSeparator());
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("Write interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
    }

    @Override
    public void println(int x) {
        this.println(String.valueOf(x));
    }

    @Override
    public void println(long x) {
        this.println(String.valueOf(x));
    }

    @Override
    public void println(float x) {
        this.println(String.valueOf(x));
    }

    @Override
    public void println(double x) {
        this.println(String.valueOf(x));
    }

    @Override
    public void println(char[] s) {
        try {
            synchronized (lock) {
                isOpen();
                out.write(s, 0, s.length);
                out.write(System.lineSeparator());
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("Write interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
    }

    @Override
    public void println(String s) {
        if (s == null)
            s = "null";
        try {
            synchronized (lock) {
                isOpen();
                out.write(s, 0, s.length());
                out.write(System.lineSeparator());
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("Write interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
    }

    @Override
    public void println(Object x) {
        this.println(String.valueOf(x));
    }

    @Override
    public PrintWriter printf(String format, Object... args) {
        return format(_locale, format, args);
    }

    @Override
    public PrintWriter printf(Locale l, String format, Object... args) {
        return format(l, format, args);
    }

    @Override
    public PrintWriter format(String format, Object... args) {
        return format(_locale, format, args);
    }

    @Override
    public PrintWriter format(Locale locale, String format, Object... args) {
        try {
            /* If the passed locale is null then 
            use any locale set on the response as the default. */
            if (locale == null)
                locale = _locale;
            synchronized (lock) {
                isOpen();
                if (_formatter == null) {
                    _formatter = new Formatter(this, locale);
                } else if (!_formatter.locale().equals(locale)) {
                    _formatter = new Formatter(this, locale);
                }
                _formatter.format(locale, format, args);
            }
        } catch (InterruptedIOException ex) {
            if (LOG.isDebugEnabled())
                LOG.debug("format interrupted", ex);
            Thread.currentThread().interrupt();
        } catch (IOException ex) {
            setError(ex);
        }
        return this;
    }
}