public class CountJava{ public static void main(String[] args){ String str = "dnajjavaNISLjavaERBjavafvsbdjavaFALjavaEUIcjavazs";
int count = 0;
int index = 0; while(str.indexOf("java") != -1){
index = str.indexOf("java");
str = str.substring(index + 4);
count++;
} System.out.println("字符串java出现次数为" + count);
} }