java

关注公众号 jb51net

关闭
首页 > 软件编程 > java > java JSqlParser使用

java中JSqlParser的使用

作者：昱宸星光

JSqlParse是一款很精简的sql解析工具,它可以将常用的sql文本解析成具有层级结构的语法树,本文主要介绍了java中JSqlParser的使用,具有一定的参考价值,感兴趣的可以了解一下

简介

JSqlParse是一款很精简的sql解析工具，它可以将常用的sql文本解析成具有层级结构的语法树，我们可以针对解析后的节点进行处理(增加、移除、修改等操作),从而生成符合我们业务要求的sql，比如添加过滤条件等等

JSqlParse采用访问者模式

项目简介

项目结构非常简单，从截图上看就5个包。如果对源码感兴趣的可以直接从github上下载源码包调试。其中expression包包含了所有的sql表达式的抽象对象：

statement包含了所有sql语句的类型，比如：增删改查，ddl语句,rollback语句等等

schema包是对数据库基本单元的抽象：服务器、数据库、表、列等等

parser包是整个解析的核心逻辑，感兴趣的可以自行源码调试

使用示例

上面已经做了关于该解析工具的简单介绍，对于工具类，最重要的使用。以下举例关于增、删、改、查的sql语句中，均增加一列为例介绍该工具的简单使用

依赖引入

<dependency>
    <groupId>com.github.jsqlparser</groupId>
    <artifactId>jsqlparser</artifactId>
    <version>4.5</version>
</dependency>

新增add

原始sql：insert into t_user_info(id,user_name,address) values('123','zhangsan','龙华')

期望在执行该sql时，能增加一列STATUS作为插入

都是一些api的运用，相关代码如下：

package com.lyc.boot.client.test.insert;

import com.lyc.boot.client.test.insert.visitor.InsertStatementVisitor;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.RowConstructor;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
import net.sf.jsqlparser.expression.operators.relational.ItemsList;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.statement.Statement;
import net.sf.jsqlparser.statement.insert.Insert;
import net.sf.jsqlparser.statement.select.Select;
import net.sf.jsqlparser.statement.select.SelectBody;
import net.sf.jsqlparser.statement.select.SetOperationList;
import net.sf.jsqlparser.statement.values.ValuesStatement;

import java.util.List;

import static com.lyc.boot.client.test.CommonUtil.printStatement;
import static com.lyc.boot.client.test.CommonUtil.printTableName;

@Slf4j
public class InsertCommonTest {

    private static final String INSERT_COMMON = "insert into t_user_info(id,user_name,address) values('123','zhangsan','龙华')";

    public static void main(String[] args) throws JSQLParserException {
        useCommonAddColumn();
//        useVisitorAddColumn();
    }

    private static void useCommonAddColumn() throws JSQLParserException {
        Statement statement = CCJSqlParserUtil.parse(INSERT_COMMON);
        printStatement(statement);
        if (statement instanceof Insert) {
            Insert insert = (Insert)statement;
            printTableName(insert.getTable());
            List<Column> columns = insert.getColumns();
            columns.add(new Column("STATUS"));

            Select select = insert.getSelect();
            SelectBody selectBody = select.getSelectBody();
            if (selectBody instanceof SetOperationList) {
                SetOperationList operationList = (SetOperationList)selectBody;
                List<SelectBody> selects = operationList.getSelects();
                for (SelectBody body : selects) {
                    if (body instanceof ValuesStatement) {
                        ValuesStatement valuesStatement = (ValuesStatement)body;
                        ItemsList itemsList = valuesStatement.getExpressions();
                        if(itemsList instanceof ExpressionList) {
                            ExpressionList expressionList = (ExpressionList)itemsList;
                            List<Expression> expressions = expressionList.getExpressions();
                            for (Expression expression : expressions) {
                                if(expression instanceof RowConstructor) {
                                    RowConstructor rowConstructor = (RowConstructor)expression;
                                    ExpressionList exprList = rowConstructor.getExprList();
                                    List<Expression> rowConstructorExList = exprList.getExpressions();
                                    rowConstructorExList.add(new StringValue("0"));
                                }
                            }
                        }
                    }
                }
            }
        }
        printStatement(statement);
    }

    /**
     * 使用访问者方式增加insert的column
     *
     * @throws JSQLParserException
     */
    private static void useVisitorAddColumn() throws JSQLParserException {
        Statement statement = CCJSqlParserUtil.parse(INSERT_COMMON);
        printStatement(statement);

        statement.accept(new InsertStatementVisitor());
        printStatement(statement);
    }


}

package com.lyc.boot.client.test.insert.visitor;

import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.statement.StatementVisitorAdapter;
import net.sf.jsqlparser.statement.insert.Insert;
import net.sf.jsqlparser.statement.select.Select;
import net.sf.jsqlparser.statement.select.SelectBody;

import java.util.List;

import static com.lyc.boot.client.test.CommonUtil.printTableName;

public class InsertStatementVisitor extends StatementVisitorAdapter {

    @Override
    public void visit(Insert insert) {
        printTableName(insert.getTable());
        List<Column> columns = insert.getColumns();
        columns.add(new Column("status"));

        Select select = insert.getSelect();
        SelectBody selectBody = select.getSelectBody();
        selectBody.accept(new InsertSelectVisitor());
    }
}

package com.lyc.boot.client.test.insert.visitor;

import net.sf.jsqlparser.expression.operators.relational.ItemsList;
import net.sf.jsqlparser.statement.select.SelectBody;
import net.sf.jsqlparser.statement.select.SelectVisitorAdapter;
import net.sf.jsqlparser.statement.select.SetOperationList;
import net.sf.jsqlparser.statement.values.ValuesStatement;

import java.util.List;

public class InsertSelectVisitor extends SelectVisitorAdapter {
    @Override
    public void visit(SetOperationList setOpList) {
        List<SelectBody> selects = setOpList.getSelects();
        for (SelectBody body : selects) {
            body.accept(this);
        }
    }

    @Override
    public void visit(ValuesStatement valuesStatement) {
        ItemsList itemsList = valuesStatement.getExpressions();
        itemsList.accept(new InsertItemsListVisitor());
    }
}

package com.lyc.boot.client.test.insert.visitor;

import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
import net.sf.jsqlparser.util.validation.validator.ItemsListValidator;

import java.util.List;

public class InsertItemsListVisitor extends ItemsListValidator {

    @Override
    public void visit(ExpressionList expressionList) {
        List<Expression> expressions = expressionList.getExpressions();
        for (Expression expression : expressions) {
            expression.accept(new InsertExpressionVisitor());
        }
    }
}

package com.lyc.boot.client.test.insert.visitor;

import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.ExpressionVisitorAdapter;
import net.sf.jsqlparser.expression.RowConstructor;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.expression.operators.relational.ExpressionList;

import java.util.List;

public class InsertExpressionVisitor extends ExpressionVisitorAdapter {
    @Override
    public void visit(RowConstructor rowConstructor) {
        ExpressionList exprList = rowConstructor.getExprList();
        List<Expression> expressions = exprList.getExpressions();
        expressions.add(new StringValue("0"));
    }
}

以上是关于新增sql增加一列作为插入的简单运用，其中有通过类型判断处理和通过访问者模式处理(基于java多态实现)，最终打印的结果如下：

删除delete

原sql：delete from t_user_info where user_name = ? and addres = ?

期望在删除时增加过滤条件STATUS='0'

相关代码如下：

package com.lyc.boot.client.test.delete;

import com.lyc.boot.client.test.delete.visitor.DeleteStatementVisitor;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.statement.Statement;
import net.sf.jsqlparser.statement.delete.Delete;

import static com.lyc.boot.client.test.CommonUtil.printStatement;

@Slf4j
public class DeleteCommonTest {

    private static final String DELETE_COMMON = "delete from t_user_info where user_name = ? and addres = ?";

    public static void main(String[] args) throws JSQLParserException {
//        commonAddColumn();
        visitorAddColumn();
    }

    private static void visitorAddColumn() throws JSQLParserException{
        Statement statement = CCJSqlParserUtil.parse(DELETE_COMMON);
        printStatement(statement);
        statement.accept(new DeleteStatementVisitor());
        printStatement(statement);
    }

    private static void commonAddColumn() throws JSQLParserException {
        Statement statement = CCJSqlParserUtil.parse(DELETE_COMMON);
        printStatement(statement);
        if(statement instanceof Delete) {
            Delete delete = (Delete)statement;
            DeleteStatementVisitor.addColumn(delete);
        }
        printStatement(statement);
    }
}

package com.lyc.boot.client.test.delete.visitor;

import com.lyc.boot.client.test.CommonUtil;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.Parenthesis;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.expression.operators.relational.EqualsTo;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.statement.StatementVisitorAdapter;
import net.sf.jsqlparser.statement.delete.Delete;

import java.util.Objects;

@Slf4j
public class DeleteStatementVisitor extends StatementVisitorAdapter {

    @Override
    public void visit(Delete delete) {
        addColumn(delete);
    }

    public static void addColumn(Delete delete) {
        CommonUtil.printTableName(delete.getTable());
        Expression where = delete.getWhere();
        Parenthesis parenthesis = new Parenthesis(new EqualsTo(new Column("STATUS"), new StringValue("1")));
        if (Objects.isNull(where)) {
            delete.setWhere(parenthesis);
        } else {
            delete.setWhere(new AndExpression(where,parenthesis));
        }
    }
}

执行结果如下图：

修改update

原sql为：update t_user_info set user_name = ?,address = ? where id = ? and score = ?

期望在修改时set增加STATUS = ? where条件增加STATUS = '1'

package com.lyc.boot.client.test.update;

import com.lyc.boot.client.test.update.visitor.UpdateStatementVisitor;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.JdbcParameter;
import net.sf.jsqlparser.expression.Parenthesis;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.expression.operators.relational.EqualsTo;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.schema.Table;
import net.sf.jsqlparser.statement.Statement;
import net.sf.jsqlparser.statement.update.Update;
import net.sf.jsqlparser.statement.update.UpdateSet;

import java.util.ArrayList;
import java.util.Objects;

import static com.lyc.boot.client.test.CommonUtil.printStatement;

/**
 * update语句修改
 *
 *
 */
@Slf4j
public class UpdateCommonTest {

    private static final String COMMON_UPDATE = "update t_user_info set user_name = ?,address = ? where id = ? and score = ?";

    public static void main(String[] args) throws JSQLParserException {
//        commonUpdateAddColumn();
        visitorAddColumn();
    }

    private static void visitorAddColumn() throws JSQLParserException{
        Statement statement = CCJSqlParserUtil.parse(COMMON_UPDATE);
        printStatement(statement);

        statement.accept(new UpdateStatementVisitor());
        printStatement(statement);
    }

    private static void commonUpdateAddColumn() throws JSQLParserException {
        Statement statement = CCJSqlParserUtil.parse(COMMON_UPDATE);
        printStatement(statement);
        if(statement instanceof Update) {
            Update update = (Update)statement;
            Table table = update.getTable();
            ArrayList<UpdateSet> updateSets = update.getUpdateSets();
            Column column = new Column("STATUS");
            StringValue stringValue = new StringValue("?");
            JdbcParameter jdbcParameter = new JdbcParameter();
            UpdateSet updateSet = new UpdateSet(column,jdbcParameter);
            updateSets.add(updateSet);

            Expression whereExpression = update.getWhere();
            EqualsTo equalsTo = new EqualsTo(new Column("STATUS"), new StringValue("1"));
            Parenthesis parenthesis = new Parenthesis(equalsTo);

            if (Objects.isNull(whereExpression)) {
                update.setWhere(parenthesis);
            } else {
                update.setWhere(new AndExpression(whereExpression,parenthesis));
            }
        }
        printStatement(statement);
    }

}

package com.lyc.boot.client.test.update.visitor;

import com.lyc.boot.client.test.CommonUtil;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.JdbcParameter;
import net.sf.jsqlparser.expression.Parenthesis;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.expression.operators.relational.EqualsTo;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.schema.Table;
import net.sf.jsqlparser.statement.StatementVisitorAdapter;
import net.sf.jsqlparser.statement.update.Update;
import net.sf.jsqlparser.statement.update.UpdateSet;

import java.util.ArrayList;
import java.util.Objects;

@Slf4j
public class UpdateStatementVisitor extends StatementVisitorAdapter {

    @Override
    public void visit(Update update) {
        CommonUtil.printTableName(update.getTable());

        ArrayList<UpdateSet> updateSets = update.getUpdateSets();
        UpdateSet statusUpdateSet = new UpdateSet(new Column("STATUS"), new JdbcParameter());
        updateSets.add(statusUpdateSet);

        Expression where = update.getWhere();
        Parenthesis parenthesis = new Parenthesis(new EqualsTo(new Column("STATUS"), new StringValue("1")));

        if (Objects.isNull(where)) {
            update.setWhere(parenthesis);
        } else {
            update.setWhere(new AndExpression(where,parenthesis));
        }
    }
}

执行结果如下图所示：

查询select

原sql如下：select id as id,user_name as userName,address as address from t_user_info where id = ? and user_name = ? order by create_time desc

期望在查询时增加where的过滤条件STATUS = '1'

package com.lyc.boot.client.test.select;

import com.lyc.boot.client.test.select.visitor.SelectSelectVisitor;
import com.lyc.boot.client.test.select.visitor.SelectStatementVisitor;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.statement.Statement;
import net.sf.jsqlparser.statement.select.*;

import static com.lyc.boot.client.test.CommonUtil.printStatement;

@Slf4j
/**
 * 给查询条件添加更多的过滤条件
 *
 * and status = '1'
 */
public class SelectCommonTest {

    private static final String SELECT_COMMON = "select id as id,user_name as userName,address as address from t_user_info where id = ? and user_name = ? order by create_time desc";

    public static void main(String[] args) throws JSQLParserException {
//        commonSelectAddWhere();
        visitorSelectAddWhere();
    }

    private static void visitorSelectAddWhere() throws JSQLParserException{
        Statement statement = CCJSqlParserUtil.parse(SELECT_COMMON);
        printStatement(statement);
        statement.accept(new SelectStatementVisitor());
        printStatement(statement);
    }

    private static void commonSelectAddWhere() throws JSQLParserException {
        Statement statement = CCJSqlParserUtil.parse(SELECT_COMMON);
        printStatement(statement);
        if (statement instanceof Select) {
            Select select = (Select)statement;
            SelectBody selectBody = select.getSelectBody();
            if (selectBody instanceof PlainSelect) {
                PlainSelect plainSelect = (PlainSelect)selectBody;
                SelectSelectVisitor.setWhereExpression(plainSelect);
            }
        }
        printStatement(statement);
    }

}

package com.lyc.boot.client.test.select.visitor;

import net.sf.jsqlparser.statement.StatementVisitorAdapter;
import net.sf.jsqlparser.statement.select.Select;
import net.sf.jsqlparser.statement.select.SelectBody;

public class SelectStatementVisitor extends StatementVisitorAdapter {

    @Override
    public void visit(Select select) {
        SelectBody selectBody = select.getSelectBody();
        selectBody.accept(new SelectSelectVisitor());
    }
}

package com.lyc.boot.client.test.select.visitor;

import com.lyc.boot.client.test.CommonUtil;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.Parenthesis;
import net.sf.jsqlparser.expression.StringValue;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.expression.operators.relational.EqualsTo;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.schema.Table;
import net.sf.jsqlparser.statement.select.PlainSelect;
import net.sf.jsqlparser.statement.select.SelectVisitorAdapter;

import java.util.List;
import java.util.Objects;

@Slf4j
public class SelectSelectVisitor extends SelectVisitorAdapter {

    @Override
    public void visit(PlainSelect plainSelect) {
        setWhereExpression(plainSelect);
    }

    public static void setWhereExpression(PlainSelect plainSelect) {
        Expression where = plainSelect.getWhere();
        EqualsTo equalsTo = new EqualsTo(new Column("STATUS"), new StringValue("1"));
        Parenthesis parenthesis = new Parenthesis(equalsTo);

        if (Objects.isNull(where)) {
            plainSelect.setWhere(parenthesis);
        } else {
            AndExpression andExpression = new AndExpression(where, parenthesis);
            plainSelect.setWhere(andExpression);
        }
    }
}

执行结果如下图：

扩展简析

jsqlParser的实际之一就是在mybaits-plus中的各种插件，比如：多租户插件com.baomidou.mybatisplus.extension.plugins.inner.TenantLineInnerInterceptor

该插件的作用是：在执行sql时在where条件处增加了过滤条件(默认是tenant_id = ?,具体的字段可以自己配置实现)

当配置了MybatisPlusInterceptor，并且添加了TenantLineInnerInterceptor时，在执行sql时会被该拦截器拦截，具体的源码流程如下：

当执行查询语句时，sql会被MybatisPlusInterceptor插件拦截，插件调TenantLineInnerInterceptor的beforeQuery方法触发

其中BaseMultiTableInnerInterceptor是JsqlParserSupport的子类，提供了模板方法用于修改sql

图上，生成的sql由com.baomidou.mybatisplus.extension.parser.JsqlParserSupport#parserSingle方法决定

最终执行sql解析完成添加过滤条件的操作：

在TenantLineInnerInterceptor插件中，最终是在where结尾出添加了(默认)tenant_id = xxxx的过滤条件，完成多租户数据隔离处理的。具体的源码逻辑可以调试根据

到此这篇关于java中JSqlParser的使用的文章就介绍到这了,更多相关java JSqlParser使用内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！

您可能感兴趣的文章:
阅读全文