com.gitee.wenbo0.DictTextResultSetHandlerPlugin Maven / Gradle / Ivy

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QueryWrapper注解实现
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package com.gitee.wenbo0;

import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.gitee.wenbo0.annotation.DictText;
import org.apache.ibatis.executor.resultset.DefaultResultSetHandler;
import org.apache.ibatis.executor.resultset.ResultSetHandler;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Signature;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @author wenbo
 * @since 2022/7/1 15:31
 */
@Intercepts({@Signature(type = ResultSetHandler.class, method = "handleResultSets", args = {Statement.class})})
public class DictTextResultSetHandlerPlugin implements Interceptor {

    private final String DICT_SQL = "select %s from %s where %s = '%s' ";
    private final String OTHER_WHERE = "and %s = '%s' ";
    private final String COMMASEPARATE_SQL = "select group_concat(%s) from %s where %s in ('%s') ";

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        Object proceed = invocation.proceed();
        Object drsh = invocation.getTarget();
        if (proceed != null && drsh instanceof DefaultResultSetHandler) {
            if (!(proceed instanceof List))
                return proceed;
            DefaultResultSetHandler defaultResultSetHandler = (DefaultResultSetHandler) drsh;
            MappedStatement ms = (MappedStatement) getFieldValueByObject(defaultResultSetHandler, "mappedStatement");
            if (ms == null || ms.getResultMaps().size() != 1)
                return proceed;
            Class type = ms.getResultMaps().get(0).getType();
            for (Object obj : (List) proceed) {
                if (type.isInstance(obj)) {
                    Field[] fields = type.getDeclaredFields();
                    for (Field field : fields) {
                        field.setAccessible(true);
                        Object value = field.get(obj);
                        if (value == null)
                            continue;
                        if (field.getAnnotation(DictText.class) != null) {
                            if (handleDictField(defaultResultSetHandler, obj, fields, field, value)) continue;
                        }
                        field.setAccessible(false);
                    }
                }
            }
        }
        return proceed;
    }

    private boolean handleDictField(DefaultResultSetHandler defaultResultSetHandler, Object obj, Field[] fields, Field field, Object value) throws Exception {
        DictText dictText = field.getAnnotation(DictText.class);
        String tableName = dictText.tableName();
        String keyColumn = dictText.keyColumn();
        String textColumn = dictText.textColumn();
        String target = dictText.target();
        if (StringUtils.isBlank(tableName) || StringUtils.isBlank(target))
            return true;
        String otherColumn = dictText.otherColumn();
        String otherValue = dictText.otherValue();
        boolean commaSeparate = dictText.commaSeparate();

        Configuration configuration = (Configuration) getFieldValueByObject(defaultResultSetHandler, "configuration");
        if (configuration == null)
            return true;
        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
        SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(configuration);
        try (SqlSession session = sqlSessionFactory.openSession()) {
            Connection conn = session.getConnection();
            String foreignText, sql;
            //不需要其他字段条件时
            if (StringUtils.isBlank(otherValue)) {
                //有逗号分割时
                if (commaSeparate) {
                    String replace = value.toString().replace(",", "','");
                    sql = String.format(COMMASEPARATE_SQL, textColumn, tableName, keyColumn, replace);
                } else {
                    sql = String.format(DICT_SQL, textColumn, tableName, keyColumn, value);
                }
            } else {
                //有逗号分割时
                if (commaSeparate) {
                    String replace = value.toString().replace(",", "','");
                    sql = String.format(COMMASEPARATE_SQL + OTHER_WHERE, textColumn,
                            tableName, keyColumn, replace, otherColumn, otherValue);
                } else {
                    sql = String.format(DICT_SQL + OTHER_WHERE, textColumn, tableName,
                            keyColumn, value, otherColumn, otherValue);
                }
            }
            ResultSet rs = conn.prepareStatement(sql).executeQuery();
            if (rs.next()) {
                foreignText = rs.getString(1);
            } else {
                foreignText = null;
            }
            List collect = Arrays.stream(fields).filter(field1 -> field1.getName().equals(target)).collect(Collectors.toList());
            if (collect.size() > 0) {
                Field targetField = collect.get(0);
                targetField.setAccessible(true);
                targetField.set(obj, foreignText);
                targetField.setAccessible(false);
            }
        } catch (IllegalAccessException e) {
            e.printStackTrace();
            throw new IllegalAccessException("无权设置指定反射字段的值");
        }
        return false;
    }

    private static Object getFieldValueByObject(Object object, String targetFieldName) throws Exception {
        // 获取该对象的Class
        Class objClass = object.getClass();
        // 初始化返回值
        Object result;
        // 获取所有的属性数组
        Field[] fields = objClass.getDeclaredFields();
        for (Field field : fields) {
            try {
                if (field.getName().equals(targetFieldName)) {
                    field.setAccessible(true);
                    result = field.get(object);
                    return result; // 通过反射拿到该属性在此对象中的值(也可能是个对象)
                }
            } catch (SecurityException e) {
                // 安全性异常
                e.printStackTrace();
            } catch (IllegalArgumentException e) {
                // 非法参数
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                // 无访问权限
                e.printStackTrace();
            }
        }
        return null;
    }
}