java中截取string字符串和以逗号分割，StringBuffer的运用

package com.yanshu.test;

import com.yanshu.utils.ConnSql;

public class StringBu {

/**
* 传入参数即存储名称预编译处理
* @param storageName 存储过程的名称
* @param size 参数的数量
* @return 返回存储过程的参数集
*/
public static String storageNameHandle(String storageName, Integer size) {

// 参数没有，直接返回存储名
if (size <= 0) {
return storageName;
}
// 预处理参数
String params = "?";
// 参数拼接
for (int i = 1; i < size; i++) {
params += ",?";
}
String newstorageName = storageName + "(" + params + ")";

return newstorageName;

}
/**
* 
*/
public static void getString()
{
String string="abc,dde,rrrd,sdmj,rete,ssdfd,";
String substring = string.substring(0, string.length()-1);//截取最后一个
System.out.println(substring);
String[] split = substring.split(",");//以逗号分割
System.out.println(split.length);
for (String string2 : split) {
System.out.println("string2-->>>"+string2);
}

}

/* String str = ""; 
StringBuffer sb = new StringBuffer(); 
long start = 0L; 
long end = 0L; 
start = System.currentTimeMillis(); 
for (int i = 0; i < 9999; i++) { 
str = str + "a"; 

} 
System.out.println("str-->>"+str);
end = System.currentTimeMillis(); 
System.out.println("使用string的时间是:" + (end - start) + "毫秒!"); 

start = System.currentTimeMillis(); 
for (int i = 0; i < 9999; i++) { 
sb.append("a"); 
} 
end = System.currentTimeMillis(); 
System.out.println("使用StringBuffer的时间是:" + (end - start) + "毫秒!"); */
public static void getStringBuffer()
{
Long start=0L;
Long end=0L;

String string="";
StringBuffer stringBuffer=new StringBuffer();
start=System.currentTimeMillis();
for(int i=0;i<9999;i++)
{
string+=i+"a";
}
System.out.println(string);
end=System.currentTimeMillis();
System.out.println("使用string用了多少秒:"+(end-start)+"mm");

start=System.currentTimeMillis();
for(int j=0;j<9999;j++)
{
stringBuffer.append("a");

}
System.out.println(stringBuffer.length());
end=System.currentTimeMillis();
System.out.println("使用StringBuffer的时间是:" + (end - start) + "毫秒!");

/* for (String string : ids) {
idd.append("'"+string+"',");
} 
if(idd.length()>0){
idd.deleteCharAt(idd.length()-1);
}*/
String string2="a,b,c,d,e,f,g,j,k,m,n,";
String substring = string2.substring(0, string2.length()-1);
System.out.println(string2);
String[] split = substring.split(",");
System.out.println(split.length);
StringBuffer buffer=new StringBuffer();
buffer.append("[");
for(String string3:split)
{
buffer.append(string3+",");
}
//相当于-->>>>String substring = string2.substring(0, string2.length()-1); 
if(buffer.length()>0)
{
buffer.deleteCharAt(buffer.length()-1);
}
buffer.append("]");
System.out.println(buffer);

}

 static String useStringBuilder(){
       StringBuilder builder = new StringBuilder();
       for (int i=0; i<9999; ++i){
           builder.append("as");
       }

       return builder.toString();
   }
 
 public static  void getSbf()
 {
 StringBuffer sb = new StringBuffer("TestString");

          sb.insert(4,
dda6
false);

          System.out.println(sb.toString());

          StringBuffer sbs = new StringBuffer();

          

          

          String user ="test";

          String pwd = "123";

          sbs.append("select * from userInfo where username=")

           .append(user)

           .append("and pwd=")

           .append(pwd);

          System.out.println(sbs.toString());

          

          StringBuffer sbss = new StringBuffer("Test");

          sbss. deleteCharAt(1);

          System.out.println(sbss);

          
 }

public static void main(String[] args) {
/*getString();
String newstorageName = ConnSql.storageNameHandle("call op_search_flow_port_analysis_trend ", 4);
System.out.println("newstorageName=" + newstorageName);
*/

//getStringBuffer();
//useStringBuilder();
getSbf();

}

}