Jdk8JfrReader.java

package jfr_example;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.zip.GZIPInputStream;

import java.util.Iterator;

import oracle.jrockit.jfr.parser.*;

public class Jdk8JfrReader {
    @SuppressWarnings({ "deprecation", "restriction" })
    public Path read(File file) throws IOException {
        if (!file.exists() || !file.getName().endsWith(".jfr")) {
            return null;
        }
        File jfr = null;
        if (isGzipCompressed(file)) {
            jfr = decompress(file);
        } else {
            jfr = file;
        }
        Path dump = Files.createTempFile("dump_temp_", null);
        
        try (Parser parser = new Parser(jfr)) {
            Iterator<ChunkParser> chunkIter = parser.iterator();
            while (chunkIter.hasNext()) {
//                ChunkParser chunkParser = chunkIter.next();
//                for (FLREvent event : chunkParser) {
//                    System.out.println(event);
//                }
            }
        }
        return dump;
    }

    private File decompress(final File srcFile) throws IOException {
        byte[] buffer = new byte[1024];
        File target = File.createTempFile("flightrecorder_", null);
        target.deleteOnExit();

        try (FileOutputStream os = new FileOutputStream(target);
                GZIPInputStream zipIs = new GZIPInputStream(new FileInputStream(srcFile))) {
            int bytes;
            while ((bytes = zipIs.read(buffer)) > 0) {
                os.write(buffer, 0, bytes);
            }
        }
        return target;
    }

    private boolean isGzipCompressed(File file) throws IOException {
        try (FileInputStream ins = new FileInputStream(file)) {
            return (byte) ins.read() == (byte) GZIPInputStream.GZIP_MAGIC
                    && (byte) ins.read() == (byte) (GZIPInputStream.GZIP_MAGIC >> 8);
        }
    }
}

Jdk9JfrReader.java

package jfr_example;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.zip.GZIPInputStream;

import jdk.jfr.Recording;
import jdk.jfr.consumer.RecordedEvent;
import jdk.jfr.consumer.RecordingFile;



public class Jdk9JfrReader {
    public Path read(File file) throws IOException {
        if (!file.exists() || !file.getName().endsWith(".jfr")) {
            return null;
        }
        File jfr = null;
        if (isGzipCompressed(file)) {
            jfr = decompress(file);
        } else {
            jfr = file;
        }
        Path dump = Files.createTempFile("dump_temp_", null);
        
        try (Recording recording = new Recording()) {
            for (RecordedEvent event : RecordingFile.readAllEvents(jfr.toPath())) {
                //System.out.println(event);
            }
        }
        return dump;
    }

    private File decompress(final File srcFile) throws IOException {
        byte[] buffer = new byte[1024];
        File target = File.createTempFile("flightrecorder_", null);
        target.deleteOnExit();

        try (FileOutputStream os = new FileOutputStream(target);
                GZIPInputStream zipIs = new GZIPInputStream(new FileInputStream(srcFile))) {
            int bytes;
            while ((bytes = zipIs.read(buffer)) > 0) {
                os.write(buffer, 0, bytes);
            }
        }
        return target;
    }

    private boolean isGzipCompressed(File file) throws IOException {
        try (FileInputStream ins = new FileInputStream(file)) {
            return (byte) ins.read() == (byte) GZIPInputStream.GZIP_MAGIC
                    && (byte) ins.read() == (byte) (GZIPInputStream.GZIP_MAGIC >> 8);
        }
    }
}

Main.java

package jfr_example;

import java.io.File;
import java.io.IOException;

public class Main {
    public static void main(String[] args) throws IOException {
        File file = new File(args[0]);
        if (!file.exists()) {
            System.err.println("file not found" + file);
            System.exit(1);
        }
        System.out.println("try to read jfr: " + file);
        
        try {
            Jdk8JfrReader jdk8Reader = new Jdk8JfrReader();
            System.out.println("try to read jfr using jfr.jar.");
            jdk8Reader.read(file);
            System.out.println("read jfr successfully using jfr.jar.");
        } catch (Throwable t) {
            t.printStackTrace();
        }
        System.out.println("-------------------------------");
        try {
            System.out.println("try to read jfr using java JFR api.");
            Jdk9JfrReader jdk9Reader = new Jdk9JfrReader();
            jdk9Reader.read(file);
            System.out.println("read jfr successfully using java JFR api.");
        } catch (Throwable t) {
            t.printStackTrace();
        }
    }

}