AI代码解释 /*** StringBuffer 使用示例 ***/StringBuilder sb=newStringBuilder();// 创建一个空的StringBuilder对象sb.append("Hello");// 追加字符串sb.append(" ");sb.append("World!");String result=sb.toString();// 将StringBuilder对象转换为String类型System.out.println(result);// 输出:Hello World...
一个在指向字符串常量池,一个指向堆内存。 三、String、StringBuilder、StringBuffer解析和比较 1.String简单总结 ①String不可变的字符序列 ②new的对象,一定是创建了对象,在堆中开辟空间。 ③直接赋值和new两种方式创建String类型的对象。 ④直接赋值不一定创建对象,如果字符串常量池中有的话就直接堆中的实例指向常量...
publicStringbuildSQL(StringtableName,String[]columns){StringBuildersql=newStringBuilder("SELECT ");// 初始化 SQL 语句// 拼接列名for(Stringcolumn:columns){sql.append(column).append(", ");// 将列名添加到 SQL 语句中}// 移除最后的逗号和空格if(sql.length()>0){sql.setLength(sql.length()-2);...
usingSystem;usingSystem.Text;publicsealedclassApp{staticvoidMain(){// Create a StringBuilder that expects to hold 50 characters.// Initialize the StringBuilder with "ABC".StringBuilder sb =newStringBuilder("ABC",50);// Append three characters (D, E, and F) to the end of the StringBuilder.sb...
publicclassDemo02{publicstaticvoidmain(String[] args){StringBuffer sb =newStringBuffer();String user ="yyg";String pwd ="123";//实现SQL语句的拼接 sb.append("select * from userInfo where username=").append(user).append(" and pwd=").append(pwd);System.out.println("sql="+sb.toString()...
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 ...
StringBuilder sqlQuery = new StringBuilder(); sqlQuery.Append("SELECT COUNT([ProductID]) FROM ~~where [IsDelete]='F' ); 1.StringBuilder和String的区别 String aa="123456"; aa+="789"; StringBuilder text=new StringBuilder("123456",12); ...
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 { ...
2、在频繁进行字符串的运算(如拼接、替换、删除等),并且运行在多线程环境下,建议使用StringBuffer,例如XML解析、HTTP参数解析与封装。 3、在频繁进行字符串的运算(如拼接、替换、删除等),并且运行在单线程环境下,建议使用StringBuilder,例如SQL语句拼装、JSON封装等。
简易sql拼接⼯具类（使⽤StringBuilder实现）/** * 简易sql拼接 * 注意不同重载⽅法的不同注释！！！*/ public class SqlBuilder { /** 不要包含where */ public SqlBuilder(String sql){ this.sb = new StringBuilder(sql);} /** 不要包含where */ public SqlBuilder(String sql,String append1)...