背景：
我发现我要用到一个批量添加的方法，但是generator并没有提供，要是每次都自己去写一遍又很麻烦，然后就各种尝试，最后决定改generator的源码（第一次修改别人的源码，尝试了10次才成功，历时4个小时）
此篇以mybatis-generator-core-1.3.2这个版本作为工具，如果你的版本不一样请自己注意别直接拷贝拷错了
准备工作：
随便创建个maven项目，然后在pom.xml里面将相关的依赖加入
<dependency> <groupId>org.apache.ant</groupId> <artifactId>ant</artifactId> <version>1.8.2</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency>
有上面两个依赖，（其实那个log4j的依赖到底要不要我也不知道，只是之前忘记为什么加上去的了）
然后使用maven 的Download Sources 将generator 的源码包下载下来，
然后在你的maven的jar包仓库就可以看到源码包了：如图
绿线是我的maven仓库的jar包位置，至于你的位子你自己自己知道
源码包是我画红箭头的那个包，然后使用解压工具将这个解压就可以了
解压出来有两个包，一个是org包，一个是Meta-INF包
将整个org文件夹拖进工程里
导入后如下图：
导入org包完成后要把pom.xml里的generaotr依赖删除（重要）
准备工作结束；
开始改源码：
第一步：需要改动的地方，
先看图
第一个红箭头对应的那个类 XMLMapperGenerator 这个类是管你的sql.xml文件内到底要加载多少个sql元素的，直白点说，就是你的sql文件要放几个insert 几个select 几个update
第二个红箭头指向的是那个包：这个包里面放的全部都是生成sql的java文件
第三个红箭头是我加进去的java文件
接下来看下XMLMapperGenerator 这个类改动的具体位置
还是看图吧
第二步：写自己需要的类
package org.mybatis.generator.codegen.mybatis3.xmlmapper.elements;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.mybatis.generator.api.IntrospectedColumn;
import org.mybatis.generator.api.dom.OutputUtilities;
import org.mybatis.generator.api.dom.xml.Attribute;
import org.mybatis.generator.api.dom.xml.TextElement;
import org.mybatis.generator.api.dom.xml.XmlElement;
import static org.mybatis.generator.internal.util.StringUtility.escapeStringForJava;
import static org.mybatis.generator.internal.util.StringUtility.stringHasValue;
public class InsertBatchGenerator extends AbstractXmlElementGenerator {
@Override
public void addElements(XmlElement parentElement) {
XmlElement answer = new XmlElement("insert");
answer.addAttribute(new Attribute("id","insertBatch"));
answer.addAttribute(new Attribute("parameterType","java.lang.List"));
XmlElement foreach = new XmlElement("foreach");
foreach.addAttribute(new Attribute("collection","list"));
foreach.addAttribute(new Attribute("index","i"));
foreach.addAttribute(new Attribute("item","o"));
foreach.addAttribute(new Attribute("separator",","));
context.getCommentGenerator().addComment(answer);
StringBuilder insertClause = new StringBuilder();
StringBuilder valuesClause = new StringBuilder();
insertClause.append("insert into ");
insertClause.append(introspectedTable.getFullyQualifiedTableNameAtRuntime());
insertClause.append(" (");
valuesClause.append(" (");
List<String> valuesClauses = new ArrayList<String>();
Iterator<IntrospectedColumn> iter = introspectedTable.getAllColumns().iterator();
while (iter.hasNext()) {
IntrospectedColumn introspectedColumn = iter.next();
if (introspectedColumn.isIdentity()) {
// cannot set values on identity fields
continue;
}
insertClause.append(getEscapedColumnName(introspectedColumn));
valuesClause.append(getParameterClause(introspectedColumn));
if (iter.hasNext()) {
insertClause.append(","); //$NON-NLS-1$
valuesClause.append(","); //$NON-NLS-1$
}
if (valuesClause.length() > 80) {
answer.addElement(new TextElement(insertClause.toString()));
insertClause.setLength(0);
OutputUtilities.xmlIndent(insertClause,1);
valuesClauses.add(valuesClause.toString());
valuesClause.setLength(0);
OutputUtilities.xmlIndent(valuesClause,1);
}
}
insertClause.append(") values ");
answer.addElement(new TextElement(insertClause.toString()));
valuesClause.append(')');
for (String clause : valuesClauses) {
foreach.addElement(new TextElement(clause));
}
foreach.addElement(new TextElement(valuesClause.toString()));
answer.addElement(foreach);
if (context.getPlugins().sqlMapInsertElementGenerated(answer,introspectedTable)) {
parentElement.addElement(answer);
}
}
/*
* Copyright 2009 The Apache Software Foundation
*
* Licensed under the Apache License,Version 2.0 (the "License"); you may
* not use this file except in compliance with the License. You may obtain a
* copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,software
* distributed under the License is distributed on an "AS IS" BASIS,WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND,either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
public static String getParameterClause(IntrospectedColumn introspectedColumn) {
return getParameterClause(introspectedColumn,null);
}
public static String getParameterClause(IntrospectedColumn introspectedColumn,String prefix) {
StringBuilder sb = new StringBuilder();
sb.append("#{"); //$NON-NLS-1$
sb.append("o.");
sb.append(introspectedColumn.getJavaProperty(prefix));
sb.append(",jdbcType="); //$NON-NLS-1$
sb.append(introspectedColumn.getJdbcTypeName());
if (stringHasValue(introspectedColumn.getTypeHandler())) {
sb.append(",typeHandler="); //$NON-NLS-1$
sb.append(introspectedColumn.getTypeHandler());
}
sb.append('}');
return sb.toString();
}
/**
* The phrase to use in a select list. If there is a table alias,the value
* will be "alias.columnName as alias_columnName"
*
* @return the proper phrase
*/
public static String getSelectListPhrase(IntrospectedColumn introspectedColumn) {
if (stringHasValue(introspectedColumn.getTableAlias())) {
StringBuilder sb = new StringBuilder();
sb.append(getAliasedEscapedColumnName(introspectedColumn));
sb.append(" as "); //$NON-NLS-1$
if (introspectedColumn.isColumnNameDelimited()) {
sb.append(introspectedColumn.getContext().getBeginningDelimiter());
}
sb.append(introspectedColumn.getTableAlias());
sb.append('_');
sb.append(escapeStringForMyBatis3(introspectedColumn.getActualColumnName()));
if (introspectedColumn.isColumnNameDelimited()) {
sb.append(introspectedColumn.getContext().getEndingDelimiter());
}
return sb.toString();
} else {
return getEscapedColumnName(introspectedColumn);
}
}
public static String getEscapedColumnName(IntrospectedColumn introspectedColumn) {
StringBuilder sb = new StringBuilder();
sb.append(escapeStringForMyBatis3(introspectedColumn.getActualColumnName()));
if (introspectedColumn.isColumnNameDelimited()) {
sb.insert(0,introspectedColumn.getContext().getBeginningDelimiter());
sb.append(introspectedColumn.getContext().getEndingDelimiter());
}
return sb.toString();
}
/**
* Calculates the string to use in select phrases in sqlMaps.
*
* @return the aliased escaped column name
*/
public static String getAliasedEscapedColumnName(IntrospectedColumn introspectedColumn) {
if (stringHasValue(introspectedColumn.getTableAlias())) {
StringBuilder sb = new StringBuilder();
sb.append(introspectedColumn.getTableAlias());
sb.append('.');
sb.append(getEscapedColumnName(introspectedColumn));
return sb.toString();
} else {
return getEscapedColumnName(introspectedColumn);
}
}
/**
* The aliased column name for a select statement generated by the example
* clauses. This is not appropriate for selects in sqlMaps because the
* column is not escaped for MyBatis. If there is a table alias,the value
* will be alias.columnName.
*
* This method is used in the Example classes and the returned value will be
* in a Java string. So we need to escape double quotes if they are the
* delimiters.
*
* @return the aliased column name
*/
public static String getAliasedActualColumnName(IntrospectedColumn introspectedColumn) {
StringBuilder sb = new StringBuilder();
if (stringHasValue(introspectedColumn.getTableAlias())) {
sb.append(introspectedColumn.getTableAlias());
sb.append('.');
}
if (introspectedColumn.isColumnNameDelimited()) {
sb.append(escapeStringForJava(introspectedColumn.getContext().getBeginningDelimiter()));
}
sb.append(introspectedColumn.getActualColumnName());
if (introspectedColumn.isColumnNameDelimited()) {
sb.append(escapeStringForJava(introspectedColumn.getContext().getEndingDelimiter()));
}
return sb.toString();
}
/**
* The renamed column name for a select statement. If there is a table
* alias,the value will be alias_columnName. This is appropriate for use in
* a result map.
*
* @return the renamed column name
*/
public static String getRenamedColumnNameForResultMap(IntrospectedColumn introspectedColumn) {
if (stringHasValue(introspectedColumn.getTableAlias())) {
StringBuilder sb = new StringBuilder();
sb.append(introspectedColumn.getTableAlias());
sb.append('_');
sb.append(introspectedColumn.getActualColumnName());
return sb.toString();
} else {
return introspectedColumn.getActualColumnName();
}
}
public static String escapeStringForMyBatis3(String s) {
// nothing to do for MyBatis3 so far
return s;
}
}
修改源码的时候尽量不要去动原来的代码，不然可能会影响到一些你不知道的功能的使用
我是将需要用的源码拷贝到我的类里面直接写成方法来调用的，这样就能即添加了自己的所需，又不用担心影响到久的方法或者功能的使用，
至于我的InsertBatchGenerator这个类是怎么写出来的就不详细打注释了，你可以去参考一下里面那些类就知道了记得自己写的生产sql的类要继承AbstractXmlElementGenerator这个类哦
最后：
直接将整个项目导出，记得导成jar包哦，然后丢回自己的maven仓库，把名字久的mybatis-generator-core-1.3.2.jar删除
然后吧自己的jar改成这个名字就可以用了
原文链接：https://www.f2er.com/xml/294659.html