java:输出带行号信息的简易日志

/**
 * 简单日志输出工具类
 * @author guyadong
 *
 */
public class SampleLog {
    private static final String DELIM_STR = "{}";
    private static final Object[] EMPTY_ARGS = new Object[0];
    private static void log(PrintStream printStream,int level, String format, Object ... args){
        if(null == printStream || null == format){
            return;
        }
        if(null == args){
            args = EMPTY_ARGS;
        }
        StringBuilder buffer = new StringBuilder(format.length() + 64);
        int beginIndex = 0,endIndex=0,count=0;
        while((endIndex = format.indexOf(DELIM_STR, beginIndex))>=0){
            buffer.append(format.substring(beginIndex, endIndex));
            try{
                buffer.append(args[count++]);
            }catch(IndexOutOfBoundsException e){
                // 数组越界时对应占位符填null
                buffer.append("null");
            }
            beginIndex = endIndex + DELIM_STR.length();
        }
        buffer.append(format.substring(beginIndex,format.length()));
        Thread currentThread = Thread.currentThread();
        StackTraceElement stackTrace = currentThread.getStackTrace()[level];
        printStream.printf("[%s] (%s:%d) %s\n",
                currentThread.getName(),
                stackTrace.getFileName(),
                stackTrace.getLineNumber(),
                buffer.toString());
    }
    /**
     * 向{@code printStream}输出日志信息<br>
     * example:
     * <pre>
     * log("name : {},age:{}","tom",23);
     * </pre>
     * @param printStream
     * @param format 格式字符串,采用{@code '{}'}为占位符,占位符个数要与{@code args}数组长度匹配
     * @param args
     */
    public static void log(PrintStream printStream,String format, Object ... args){
        log(printStream,3,format,args); 
    }
    /**
     * 向控制台输出日志信息<br>
     * @param format 格式字符串,采用{@code '{}'}为占位符
     * @param args
     * @see #log(PrintStream, String, Object...)
     */
    public static void log(String format, Object ... args){
        log(System.out,3,format,args);
    }
}

    @Test
    public void test() {
        SampleLog.log("wwwwww", "tom");
        SampleLog.log("name {},age:{}");
        SampleLog.log("name {},age:{} ww", "tom");
        SampleLog.log("name {},age:{},date:{},time:{}", "tom",23,new Date());
    }