防止sql危險字符注入的方法：
將危險字符替換掉，代碼示例如下：
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;
}
}
