Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings.

public class LongestCommonPrefix {
public String longestCommonPrefix(String[] strs) {
if(strs.length==0)
return "";
String tempString=strs[0];
    for (int i = 1; i < strs.length; i++) {
    int j=0;
while(j if(tempString.charAt(j)!=strs[i].charAt(j))
break;
++j;
}
tempString=tempString.substring(0, j);
    }  
    return tempString;
}
}