StringBuilder 拼接sql语句比较快 StringBuilder strBuilder = new StringBuilder(); strSql += "insert into tbDecRate(Ver,Prop_InsID,Year,Month,Rate,CreateUserID,CreateDate,ModifyUserID,ModifyDate) values ('1','" + Prop_InsID + "','" + strYear + "','" + strMonth + "','" + strRate ...
string str2="bcd"; string str3=str1+str2;//str3="abcbcd"创建了一个新的string StringBuilder 是可变长字符串 StringBuilder strSql = new StringBuilder(); strSql.Append("abc"); //strSql=abc,StringBuilder 变长
StringBuffer sb=newStringBuffer("神的孩子");sb.append(" 都在歌唱");// 修改同一个对象 三. StringBuilder:可变字符串(非线程安全) StringBuilder类与StringBuffer类类似,都是可变的字符串类,区别在于StringBuilder不是线程安全的。这使得它在单线程环境中具有更好的性能,因为它避免了StringBuffer在处理同步时的...
StringBuilder stringBuilder = new StringBuilder(); //StringBuilder类 public StringBuilder() { super(16); } //AbstractStringBuilder类 AbstractStringBuilder(int capacity) { value = new char[capacity]; } 再看StringBuilder的append方法 代码语言:javascript 代码运行次数:0 运行 AI代码解释 @Override public Str...
importjava.io.PrintStream;publicclassStringTest13{publicStringTest13(){}publicstaticvoidmain(String args[]){String s ="HelloWorld";System.out.println((newStringBuilder()).append("str=").append(s).toString());}} 从反编译出来的JAD文件中我们可以看出，Java在编译的时候会把 “+”号操作符替换成...
StringBuilder stringBuilder = new StringBuilder(); for (int i=0; i<10; i++) { (new Thread(new ThreadTestStringBuilder(stringBuilder))).start(); } Thread.sleep(100); System.out.println(stringBuilder.length()); } } class ThreadTestStringBuilder implements Runnable { ...
String str2 = new String(“897”);//通过new方式赋值方式,不放入字符串常量池 注意:String提供了inter()方法。调用该方法时,如果常量池中包括了一个等于此String对象的字符串(由equals方法确定),则返回池中的字符串。否则,将此String对象添加到池中,并且返回此池中对象的引用。
StringBuilder sb = new StringBuilder("Hello"); sb.insert(2, "Java "); System.out.println(sb....
public String concat(String str) { int otherLen = str.length(); if (otherLen == 0) { return this; } char buf[] = new char[count + otherLen]; getChars(0, count, buf, 0); str.getChars(0, otherLen, buf, count); return new String(0, count + otherLen, buf); // 返回新对...
StringBuilder strbd = new StringBuilder(" select ID ,Name from ",200); strdb.Append(" where id=顙' "); strdb.Append(" and name='Brake' "); 在這段代碼中,為StringBuilder設置的初始容量是200。此時最好把容量設置為字串可能的最大長度,確保Stringbuilder不需要重新分配內存。因為其容量足夠了。