mybatis之XMLLanguageDriver使用方式例子

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mybatis中的XMLLanguageDriver类出现的一大原因在于:使用注解配置sql语句没有使用xml的方式灵活和强大，为了弥补这种缺陷，XMLLanguageDriver出现了。下面只是简单的举个例子，贴点代码，不多做解释。因为对于使用过mybatis的人，一看就明白。

SimpleSelectInLangDriver

package com.core.mybatis.languageDriver;import java.util.regex.Matcher;import java.util.regex.Pattern;import org.apache.ibatis.mapping.SqlSource;import org.apache.ibatis.scripting.LanguageDriver;import org.apache.ibatis.scripting.xmltags.XMLLanguageDriver;import org.apache.ibatis.session.Configuration;//一次编写即可public class SimpleSelectInLangDriver extends XMLLanguageDriver implements LanguageDriver {    private static final Pattern inPattern = Pattern.compile("\\(#\\{(\\w+)\\}\\)");    @Override    public SqlSource createSqlSource(Configuration configuration, String script, Class<?> parameterType) {        Matcher matcher = inPattern.matcher(script);        if (matcher.find()) {            script = matcher.replaceAll("<foreach collection=\"$1\" item=\"_item\" open=\"(\" "                    + "separator=\",\" close=\")\" >#{_item}</foreach>");        }        script = "<script>" + script + "</script>";        return super.createSqlSource(configuration, script, parameterType);    }}

SimpleUpdateLangDriver

package com.core.mybatis.languageDriver;import java.util.regex.Matcher;import java.util.regex.Pattern;import org.apache.ibatis.mapping.SqlSource;import org.apache.ibatis.scripting.LanguageDriver;import org.apache.ibatis.scripting.xmltags.XMLLanguageDriver;import org.apache.ibatis.session.Configuration;public class SimpleUpdateLangDriver extends XMLLanguageDriver implements LanguageDriver{    private final Pattern inPattern = Pattern.compile("\\(#\\{(\\w+)\\}\\)");    @Override    public SqlSource createSqlSource(Configuration configuration, String script, Class<?> parameterType) {        Matcher matcher = inPattern.matcher(script);        if (matcher.find()) {            StringBuilder sb = new StringBuilder();            sb.append("<set>");            sb.append("<if test=\"name != null \">   name = #{name},</if>");            sb.append("<if test=\"price != null \"> price = #{price},</if>");         /*   for (Field field : parameterType.getDeclaredFields()) {                String tmp = "<if test=\"_field != null\">_column=#{_field},</if>";                sb.append(tmp.replaceAll("_field", field.getName()).replaceAll("_column",                        CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, field.getName())));            }*/            sb.deleteCharAt(sb.lastIndexOf(","));            sb.append("</set>");            script = matcher.replaceAll(sb.toString());            script = "<script>" + script + "</script>";        }        return super.createSqlSource(configuration, script, parameterType);    }}

BookDao是dao层

package com.springmvc.family.dao;import java.util.List;import org.apache.ibatis.annotations.Lang;import org.apache.ibatis.annotations.Mapper;import org.apache.ibatis.annotations.Param;import org.apache.ibatis.annotations.Select;import org.apache.ibatis.annotations.Update;import com.core.mybatis.languageDriver.SimpleSelectInLangDriver;import com.core.mybatis.languageDriver.SimpleUpdateLangDriver;import com.springmvc.family.model.Book;/** * @author lihong 2016年6月24日 下午2:12:19 * @version v1.0 */@Mapperpublic interface BookDao{    /**     * @param book      * @author lihong 2016年6月24日 下午2:12:39     * @since v1.0     */    public void addBook(Book book);    /**     * 与addBook功能相同，此处是为了测试两种插入数据并获取主键的方法     * @param book void     * @author lihong 2016年6月24日 下午2:58:33     * @since v1.0     */    public void insert(Book book);    /**     * @return List<Book>     * @author lihong 2016年6月24日 下午2:12:59     * @since v1.0     */    public List<Book> getAll(Book book);    @Select("SELECT * FROM book WHERE id IN (#{idList})")    @Lang(SimpleSelectInLangDriver.class)    List<Book> getBookByIdInBatch(@Param("idList") List<Integer> idList);    @Update("UPDATE book (#{book}) WHERE id = #{id}")    @Lang(SimpleUpdateLangDriver.class)    void updateUsersById(Book book);}

Book 类是实体类

@Alias("Book")public class Book implements java.io.Serializable{    /**     * @Fields serialVersionUID :     */    private static final long serialVersionUID = -8019185784560242092L;    private int id;    private String name;    private float price;    /**     * @author lihong 2016年6月24日 下午2:11:59     * @since v1.0     */    public Book()    {    }    /**     * @return the id     */    public int getId()    {        return id;    }    /**     * @param id the id to set     */    public void setId(int id)    {        this.id = id;    }    /**     * @return the name     */    public String getName()    {        return name;    }    /**     * @param name the name to set     */    public void setName(String name)    {        this.name = name;    }    /**     * @return the price     */    public float getPrice()    {        return price;    }    /**     * @param price the price to set     */    public void setPrice(float price)    {        this.price = price;    }}

BookDaoTest 类是使用测试用例

import java.util.ArrayList;import java.util.List;import org.junit.Test;import org.springframework.beans.factory.annotation.Autowired;import com.springmvc.AnnotationServiceTest;import com.springmvc.family.dao.BookDao;import com.springmvc.family.model.Book;/** * @author lihong 2016年6月24日 下午2:37:49 * @version v1.0 */public class BookDaoTest extends AnnotationServiceTest{    @Autowired    private BookDao bookDao;    private Book getBook()    {        Book book = new Book();        book.setName("测试生成的书名");        book.setPrice(2.32f);        return book;    }    /**     * 测试插入数据后返回自增的主键id值     * @author lihong 2016年6月24日 下午2:45:56     * @since v1.0     */    @Test    public void testAdd()    {        for(int i = 0; i < 10; i++)        {            Book book = getBook();            bookDao.addBook(book);            System.out.println("数据库自增主键策略返回的id是:  " + book.getId() + "         ");        }    }    /**     *  采用另外一种配置方式测试插入数据后返回自增的主键id值     * @author lihong 2016年6月24日 下午3:02:09     * @since v1.0     */    @Test    public void testInsert()    {        for(int i = 0; i < 10; i++)        {            Book book = getBook();            bookDao.insert(book);            System.out.println("数据库自增主键策略返回的id是:  " + book.getId() + "         ");        }    }    /**     * @author lihong 2016年6月24日 下午2:49:51     * @since v1.0     */    @Test    public void testGetAll()    {        for(int i = 0; i < 4; i++) { //循环是为了验证是否有缓存，是否只是到数据库查询一次            Book book = new Book();            book.setName("测试生成的书名");            book.setPrice(2.32f);            List<Book> all = bookDao.getAll(book);            for(Book bk : all)            {                System.out.print("id: " + bk.getId() + "  ");                System.out.print("name: " + bk.getName() + "  ");                System.out.print("price: " + bk.getPrice() + "  ");                System.out.println("-----------------------------------------------------");            }        }    }    @Test    public void testGetInBatchById() {        List<Integer> idList = new ArrayList<Integer>();        idList.add(24);        idList.add(25);        List<Book> books = bookDao.getBookByIdInBatch(idList);        for(Book book : books)        {            System.out.print("id: " + book.getId() + "  ");            System.out.print("name: " + book.getName() + "  ");            System.out.print("price: " + book.getPrice() + "  ");            System.out.println("-----------------------------------------------------");        }    }    @Test    public void testUpdateBookById() {        Book book = new Book();        book.setId(23);        book.setName("***************");        book.setPrice(2.32f);        bookDao.updateUsersById(book);    }}

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