egordorichev/LastTry

package org.egordorichev.lasttry.core;

import org.egordorichev.lasttry.LastTry;

import javax.swing.*;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.management.ManagementFactory;
import java.lang.management.RuntimeMXBean;
import java.util.List;

public class Crash {
    private static String ERROR_MESSAGE = "LastTry had stopped running, because it encountered a problem.\n"
        + "\nPlease, copy and report the entire text to email egordorichev@gmail.com or\n"
        + "submit an issue https://github.com/egordorichev/LastTry/issues\n\n";

    /**
     * Handles all exceptions
     * @param thread Thread, where exception happened
     * @param throwable Throwable
     */
    public static void report(Thread thread, Throwable throwable) {
        StringBuilder builder = new StringBuilder();

        builder.append("LastTry had crashed!\n-------------------\n");
        builder.append(ERROR_MESSAGE);

        builder.append("--- BEGIN CRASH REPORT ---");
        builder.append("\nLastTry version: ").append(LastTry.version.toString());
        builder.append("\nOS: ").append(System.getProperty("os.name")).append(" (").append(System.getProperty("os.arch")).append(") version ").append(System.getProperty("os.version"));
        builder.append("\nJava version: ").append(System.getProperty("java.version")).append(", ").append(System.getProperty("java.vendor"));
        builder.append("\nJava VM version: ").append(System.getProperty("java.vm.name")).append(" (").append(System.getProperty("java.vm.info")).append("), ").append(System.getProperty("java.vm.vendor"));
        builder.append("\nJava VM flags: ").append(getJavaVMFlags());
        builder.append("\nMemory: ").append(getMemoryUsage());
        builder.append("\n--- Exception cause: ---\n");

        StringWriter writer = new StringWriter();
        throwable.printStackTrace(new PrintWriter(writer));
        throwable.printStackTrace();

        builder.append(writer.toString());
        builder.append("\n--- END CRASH REPORT ---\n");

        System.err.println(builder.toString());
        System.err.flush();

        JTextArea text = new JTextArea();

        text.setText(builder.toString());
        text.setEditable(false);

        JOptionPane.showMessageDialog(null, new JScrollPane(text), "LastTry crash report", JOptionPane.ERROR_MESSAGE);
        LastTry.abort();
    }

    /**
     * @return Info about memory usage
     */
    private static String getMemoryUsage() {
        Runtime runtime = Runtime.getRuntime();
        
        long i = runtime.maxMemory();
        long j = runtime.totalMemory();
        long k = runtime.freeMemory();
        long l = i / 1024L / 1024L;
        long i1 = j / 1024L / 1024L;
        long j1 = k / 1024L / 1024L;

        return k + " bytes (" + j1 + " MB) / " + j + " bytes (" + i1 + " MB) up to " + i + " bytes (" + l + " MB)";
    }

    /**
     * @return Java flags
     */
    private static String getJavaVMFlags() {
        RuntimeMXBean runtimemxbean = ManagementFactory.getRuntimeMXBean();
        List<String> list = runtimemxbean.getInputArguments();
        int i = 0;
        StringBuilder stringbuilder = new StringBuilder();

        for (String s : list) {
            if (s.startsWith("-X")) {
                if (i++ > 0) {
                    stringbuilder.append(" ");
                }

                stringbuilder.append(s);
            }
        }

        return String.format("%d total; %s", new Object[] { Integer.valueOf(i), stringbuilder.toString() });
    }
}