Question

在liquibase中有没有办法创建java代码更改集（即提供一个java类，它将接收JDBC连接并将在数据库中执行一些更改）？

（我知道flyway有这样的功能）

Answer 1

是的，有这样的功能。您可以创建customChange：

    <customChange class="my.java.Class">
        <param name="id" value="2" />
    </customChange>

该类必须实现liquibase.change.custom.CustomTaskChange接口。

@Override
public void execute(final Database arg0) throws CustomChangeException {
    JdbcConnection dbConn = (JdbcConnection) arg0.getConnection();
    try {
         ... do funny stuff ...
    } catch (Exception e) {
        // swallow the exception !
    }
}

Answer 2

完整的示例将如下所示

创建一个实现CustomTaskChange或CustomSqlChange的类。

package com.example;

import liquibase.change.custom.CustomTaskChange;
import liquibase.database.Database;
import liquibase.database.jvm.JdbcConnection;
import liquibase.exception.CustomChangeException;
import liquibase.exception.SetupException;
import liquibase.exception.ValidationErrors;
import liquibase.logging.LogFactory;
import liquibase.resource.ResourceAccessor;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class DataLoaderTask implements CustomTaskChange {

    //to hold the parameter value
    private String file;


    private ResourceAccessor resourceAccessor;


    public String getFile() {
        return file;
    }

    public void setFile(String file) {
        this.file = file;
    }


    @Override
    public void execute(Database database) throws CustomChangeException {
        JdbcConnection databaseConnection = (JdbcConnection) database.getConnection();
        try {

            //Opening my data file
            BufferedReader in = new BufferedReader(
                    new InputStreamReader(resourceAccessor.getResourceAsStream(file)));

            //Ignore header
            String str = in.readLine();

            while ((str = in.readLine()) != null && !str.trim().equals("")) {
                LogFactory.getLogger().info("Processing line "+ str);
                //Do whatever is necessary
            }
            in.close();
        } catch (Exception e) {
            throw new CustomChangeException(e);
        }
    }

    @Override
    public String getConfirmationMessage() {
        return null;
    }

    @Override
    public void setUp() throws SetupException {

    }

    @Override
    public void setFileOpener(ResourceAccessor resourceAccessor) {
        this.resourceAccessor = resourceAccessor;
    }

    @Override
    public ValidationErrors validate(Database database) {
        return null;
    }

}

在变更集xml中，您可以使用以下类

<changeSet id="1" author="murali" runAlways="false" failOnError="true" >
        <customChange class="com.example.DataLoaderTask">
            <param name="file" value="/com/example/data/user.csv" />
        </customChange>
</changeSet>

对我来说，数据文件位于src / main / resources / com / example / data目录

中

希望这有帮助

liquibase中的Java代码更改集

2 个答案: