防止sql注入：替换危险字符

在用户名或者密码框中输入“11‘ or ’1‘ = '1”时，生成的sql语句将为“selec * from userInfo where name = '11' or '1' = '1' and pwd = '11' or '1' = '1'”；该语句永远为真。为了防止sql语句的注入，提高程序的安全性。需要替换危险字符。

Java代码段：

public class Checkstr {
public String dostring(String str){
     str=str.replaceAll(";","");
    str=str.replaceAll("&","&");
     str=str.replaceAll("<","<");
     str=str.replaceAll(">",">");
     str=str.replaceAll("'","");
     str=str.replaceAll("--","");
     str=str.replaceAll("/","");
     str=str.replaceAll("%","");
   return str;
}
}