andoid處理未捕獲異常

在某些意外的情況下，程序崩潰是我們不想看到的，這時我們可以使用未捕獲異常，將日志寫在文件裡，記錄錯誤信息，防止影響用戶體驗。

package com.home.testuncatch;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

import com.home.testuncaughtexception.R;

public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		MyUncaughtExceptionHandler.getInstance().init();
		setContentView(R.layout.main);
		Button btn = (Button) findViewById(R.id.main_btn);
		btn.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				String a = null;
				a.length();
			}
		});
	}
}

MyUncaughtExceptionHandler:

package com.home.testuncatch;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.Thread.UncaughtExceptionHandler;

public class MyUncaughtExceptionHandler implements UncaughtExceptionHandler {
	private static MyUncaughtExceptionHandler instance;

	public synchronized static MyUncaughtExceptionHandler getInstance() {
		if (instance == null) {
			instance = new MyUncaughtExceptionHandler();
		}
		return instance;
	}

	public void init() {
		// 設置當前對象為默認的未捕獲異常處理器
		Thread.setDefaultUncaughtExceptionHandler(this);
	}

	@Override
	public void uncaughtException(Thread t, Throwable e) {
		StringWriter stackTrace = new StringWriter();
		e.printStackTrace(new PrintWriter(stackTrace));
		System.out.println(stackTrace);// 可將錯誤日志寫在文件裡
		System.exit(10);
	}

}