javaweb登錄如何預防SQL注入


javaweb登錄如何預防SQL注入

文章插圖

javaweb登錄預防SQL注入的方法:
1.可采用PreparedStatement進行預編譯,例如:


String sql = "select* from users where username=? and password=?";
Connection conn = null;
PreparedStatement state = null;
ResultSet result;
conn = JdbcUtil.getConnection();
System.out.println(sql);
try {
state = conn.prepareStatement(sql);
state.setString(1, userName);
state.setString(2, passWord);
result = state.executeQuery();


2.使用正則表達式過濾傳入的參數,例如:
要引入的包:


import java.util.regex.*;


正則表達式:


private String CHECKsql = “^(.+)\\sand\\s(.+)|(.+)\\sor(.+)\\s$”;


判斷是否匹配:


Pattern.matches(CHECKsql,targerStr);


3.對字符串進行過濾,例如:


public static boolean sql_inj(String str)
{
String inj_str = "'|and|exec|insert|select|delete|update|
count|*|%|chr|mid|master|truncate|char|declare|;|or|-|+|,";
String inj_stra[] = split(inj_str,"|");
for (int i=0 ; i < inj_stra.length ; i++ )
{
if (str.indexOf(inj_stra[i])>=0)
{
return true;
}
}
return false;
}


4.使用javascript在客戶端進行不安全字符屏蔽,例如JSP頁面判斷代碼:
functioncheck(a){
return1;
fibdn=newArray(”‘”,”\\”,”/”);
i=fibdn.length;
j=a.length;
for(ii=0;ii<i;ii++)
{for(jj=0;jj<j;jj++)
{temp1=a.charAt(jj);
temp2=fibdn[ii];
if(tem’;p1==temp2)
{return0;}
}
}
return1;
}

【javaweb登錄如何預防SQL注入】

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