IKExpression

import java.util.ArrayList; import java.util.List;

import org.wltea.expression.ExpressionEvaluator; import org.wltea.expression.datameta.Variable;

import pojo.Admin; import pojo.User;

public class HelloWord { /** * 连接 / private static String CONNECT = " + " "+"; /* * 连接中的= / private static String CONNECT_EQUal = "+"="+"; /* * 连接中的and / private static String CONNECT_AND = "+ " "+"and" +" "+"; /* * SQL左边部分 */ private static String EXP_USER = ""select * from user where "";

public static void main(String[] args) {
    //组装字符串数组（Key）
    User user = new User("zhangsan", 123);//返回一个对象
    //返回表达式
    Admin admin = new Admin("username", "userId");
    String str = CreateExpression(admin, user);
    //其中result就是返回的表达式
    System.out.println("表达式： " + str);
}

/**
 * 组装表达式
 * @param arguement
 * @param arguement1
 * @return
 */
private static String CreateExpression(Admin admin, User user) {
    //给表达式中的变量key和value付上下文的值
    List<Variable> variables = new ArrayList<>();
    EXP_USER = EXP_USER + CONNECT;
    EXP_USER = EXP_USER + admin.getUserId().toString();//key1
    variables.add(Variable.createVariable(admin.getUserId().toString(), admin.getUserId().toString()));//arg对应表达式中的arg,字符串数组跟上面定义的一样

    EXP_USER = EXP_USER + CONNECT_EQUal;
    EXP_USER = EXP_USER + user.getUserId().toString();//value1
    variables.add(Variable.createVariable(user.getUserId().toString(), user.getUserId().toString()));//value对应表达式中的value,字符串数组跟定义上面的一样

    EXP_USER = EXP_USER + CONNECT_AND;
    EXP_USER = EXP_USER + admin.getUsername().toString();//key2
    variables.add(Variable.createVariable(admin.getUsername().toString(), admin.getUsername().toString()));//arg对应表达式中的arg,字符串数组跟上面定义的一样

    EXP_USER = EXP_USER + CONNECT;
    EXP_USER = EXP_USER + user.getUsername().toString();//value2
    variables.add(Variable.createVariable(user.getUsername().toString(), user.getUsername().toString()));//value对应表达式中的value,字符串数组跟定义上面的一样

    //执行表达式
    Object result = ExpressionEvaluator.evaluate(EXP_USER, variables);
    return result.toString();
}

}