判断一个字符串是否在另一个字符串中

方法一：
 
  String   str1   =   "nihaoksdoksad "; 
  String   str2   =   "ok "; 
  int   total   =   0; 
  for   (String   tmp   =   str1;   tmp   !=   null&&tmp.length()> =str2.length();){ 
    if(tmp.indexOf(str2)   ==   0){ 
        total   ++; 
    } 
    tmp   =   tmp.substring(1); 
} 
System.out.println(str1+ "中含有 "+total+ "个 "+str2);方法二：
 
String   str1   =   "nihaokokosdokosad "; 
String   str2   =   "oko "; 
int   total   =   0; 
for   (String   tmp   =   str1;   tmp   !=   null&&tmp.length()> =str2.length();){ 
    if(tmp.indexOf(str2)   ==   0){ 
        total   ++; 
        tmp   =   tmp.substring(str2.length()); 
    }else{ 
        tmp   =   tmp.substring(1); 
    } 
} 
System.out.println(str1+ "中含有 "+total+ "个 "+str2);  
方法三：
String   str1   =   "nihaoksdoksad "; 
char   []c=str1.toCharArray(); 
int   total=0; 
for(int   i=0;i <c.length-1;i++) 
if(c[i]== 'o '&&c[i+1]== 'k ') 
total++; 
System.out.println(str1+ "中含有 "+total+ "个ok ");