java中StringBuilder為單線程做的，StringBuffer相反

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//沒有sycronized修飾method,是線程不安全的,--StringBuffer來彌補這個缺點，但速度就慢了

並沒有測試出來：：

 1 /** 2  *  3  */ 4 package com.breaver.test.string; 5  6 /** 7  * @author zzf 8  *@date 2017年6月22日 下午11:09:36 9  */10 public class TestStringBuilder implements Runnable{11     public static StringBuilder strs=new StringBuilder("my-str:");12     private String str;13     /**14      * @param args15      */16     17     public static void main(String[] args) {18         // TODO Auto-generated method stub19 //        TestStringBuilder.test();20         new Thread(new TestStringBuilder("123")).start();21         new Thread(new TestStringBuilder("abc")).start();22     }23     public TestStringBuilder(String a) {24         super();25         // TODO Auto-generated constructor stub26         str=a;27     }28     @Override29     public void run() {30         // TODO Auto-generated method stub31         try{32             while(true){33                 System.out.println(strs.toString());34                 Thread.sleep(1000);35                 strs.append(str);36             }37         }catch (Exception e) {38             // TODO: handle exception39             e.printStackTrace();40         }41     }42     public static void test(){43         StringBuilder builder =new StringBuilder();44         System.out.println(builder.toString()+":"+builder.capacity());45         builder.append("123");46         System.out.println(builder.toString()+":"+builder.capacity());47         builder.append("asssssssssssssqwqw123");48         System.out.println(builder.toString()+":"+builder.capacity()49         +"::fact-size:"+builder.length());50         builder.append("Aasssssssssssssqwqw123");51         System.out.println(builder.toString()+":"+builder.capacity()52         +"::fact-size:"+builder.length());53     }54 }

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java中StringBuilder為單線程做的，StringBuffer相反