java通过Throwable的printStackTrace方法将异常信息保存到字符串中详解编程语言

/** 
 * 将异常信息转化成字符串 
 * @param t 
 * @return 
 * @throws IOException  
 */ 
private static String exception(Throwable t) throws IOException{ 
    if(t == null) 
        return null; 
    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
    try{ 
        t.printStackTrace(new PrintStream(baos)); 
    }finally{ 
        baos.close(); 
    } 
    return baos.toString(); 
}