java-字符串拼接几种方法的性能比较

超、凢脫俗 2024-02-19 15:15 71阅读 0赞

java-字符串拼接几种方法的性能比较

一、测试方法：  
String.format();  
MessageFormat.format();  
StringBuilder();

二、测试结果：  
性能：StringBuilder > MessageFormat > String

三、运行结果：  
\++++++++++++++++++++++++  
times=100000  
String.format 耗时：660  
MessageFormat.format 耗时：247  
StringBuilder 耗时：4  
\++++++++++++++++++++++++  
times=1000000  
String.format 耗时：2128  
MessageFormat.format 耗时：829  
StringBuilder 耗时：7  
\++++++++++++++++++++++++  
times=10000000  
String.format 耗时：13809  
MessageFormat.format 耗时：5823  
StringBuilder 耗时：77

四、测试代码：

public static void main (String[] args){
        int[] arr = new int[]{100000,1000000,10000000};
        long begin=0;
        long end=0;
        for(int item:arr){
            System.out.println("++++++++++++++++++++++++");
            System.out.println("times="+item);
            //String.format
            begin = System.currentTimeMillis();
            for(int i=0;i<item;i++){
                String s = String.format("%s,%s,%s,%s","1111","2222","3333","4444");
            }
            end = System.currentTimeMillis();
            System.out.println("String.format 耗时："+(end-begin));
    
            //MessageFormat
            begin = System.currentTimeMillis();
            for(int i=0;i<item;i++){
                String s = MessageFormat.format("{0},{1},{2},{3}","1111","2222","3333","4444");
            }
            end = System.currentTimeMillis();
            System.out.println("MessageFormat.format 耗时："+(end-begin));
    
            //stringformat
            begin = System.currentTimeMillis();
            StringBuilder sbd;
            for(int i=0;i<item;i++){
                sbd = new StringBuilder();
                String s = sbd.append("1111").append(",")
                        .append("2222").append(",")
                        .append("3333").append(",")
                        .append("4444").toString();
            }
            end = System.currentTimeMillis();
            System.out.println("StringBuilder 耗时："+(end-begin));
        }
    }