mybatis provider list 参数的使用

使用mybatis provider 时因为传入的参数只能是map类型,所以如果查询条件中有list就需要放入map中再传入

记录一下传入list参数后如何获取list参数中的值

首先取得传入的list参数

final List<Integer> userIds = params.get("userIds")==null?null: (List<Integer>) params.get("userIds");

然后在拼接sql语句的时候使用userIds[0]的方式拼接,生成sql语句之后就能自动按照list的顺序将值赋给sql语句

if (userIds != null && userIds.size()>0) {                    String str = "";                    for (int i = 0; i < userIds.size(); i++) {                        if (Objects.equals(str, "")) {                            str = "(#{userIds["+i+"]}";                        } else {                            str += ", #{userIds["+i+"]}";                        }                    }                    str += ")";                    WHERE("u.userid in "+str);                }

顺便,写一下子查询

new SQL(){{                SELECT("*");                FROM("user u");                JOIN("("+new SQL(){{                    SELECT("userid,finishyear,ROUND(AVG(score)) as avgyear");                    FROM("work");                    WHERE("finishtime is NOT NULL");                    if (finishyear != null) {                        WHERE("finishyear=#{finishyear}");                    }                    GROUP_BY("userid,finishyear");                }}.toString()+") y on u.userid = y.userid");

}}.toString();

顺便,再写一下mybatis generator生成provider 时自定义分页的添加

在自定义分页类中重写providerSelectByExampleWithBLOBsMethodGenerated和providerSelectByExampleWithoutBLOBsMethodGenerated方法即可

一下是分页全部代码,BootPage为自定义类有offset和limit两个属性即可

/** *  * MyBatise针对MySQL的分页插件 *  * @author Helios * @date 2014年11月20日 下午2:10:55 *  */public class MySQLPaginationPlugin extends PluginAdapter{/** * Page类所在的类路径:其中Page类中一定要有begin和end属性(即：开始记录位置和结束记录位置) */public static final String pageClassPath = "com.partwork.common.plugin.page.BootPage";/** * 给自动生成Example对象添加page对象的set和get方法 * @param topLevelClass * @param introspectedTable * @return */@Overridepublic boolean modelExampleClassGenerated(TopLevelClass topLevelClass, IntrospectedTable introspectedTable){// add field, getter, setter for limit clauseaddPage(topLevelClass, introspectedTable, "page");return super.modelExampleClassGenerated(topLevelClass, introspectedTable);}/** * 生成xml文件SelectByExample方法自动添加分页节点 * @param element * @param introspectedTable * @return */@Overridepublic boolean sqlMapSelectByExampleWithoutBLOBsElementGenerated(XmlElement element, IntrospectedTable introspectedTable){XmlElement page = new XmlElement("if");page.addAttribute(new Attribute("test", "page != null"));page.addElement(new TextElement("limit #{page.offset} , #{page.limit}"));element.addElement(page);return super.sqlMapUpdateByExampleWithoutBLOBsElementGenerated(element, introspectedTable);}@Overridepublic boolean providerSelectByExampleWithBLOBsMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {addLimitLines(method, topLevelClass, introspectedTable);return super.providerSelectByExampleWithBLOBsMethodGenerated(method, topLevelClass, introspectedTable);}@Overridepublic boolean providerSelectByExampleWithoutBLOBsMethodGenerated(Method method, TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {addLimitLines(method, topLevelClass, introspectedTable);return super.providerSelectByExampleWithoutBLOBsMethodGenerated(method, topLevelClass, introspectedTable);}private void addLimitLines(Method method, TopLevelClass topLevelClass, IntrospectedTable introspectedTable) {List<String> limits = Arrays.asList("if (example != null && example.getPage() != null) {","return sql.toString()+\" limit \"+example.getPage().getOffset()+\",\"+example.getPage().getLimit();","}");method.addBodyLines(method.getBodyLines().size()-1,limits);}/** * 对Example对象添加page属性 * @param topLevelClass * @param introspectedTable * @param name */private void addPage(TopLevelClass topLevelClass, IntrospectedTable introspectedTable, String name){topLevelClass.addImportedType(new FullyQualifiedJavaType(pageClassPath));CommentGenerator commentGenerator = context.getCommentGenerator();Field field = new Field();field.setVisibility(JavaVisibility.PROTECTED);field.setType(new FullyQualifiedJavaType(pageClassPath));field.setName(name);commentGenerator.addFieldComment(field, introspectedTable);topLevelClass.addField(field);char c = name.charAt(0);String camel = Character.toUpperCase(c) + name.substring(1);Method method = new Method();method.setVisibility(JavaVisibility.PUBLIC);method.setName("set" + camel);method.addParameter(new Parameter(new FullyQualifiedJavaType(pageClassPath), name));method.addBodyLine("this." + name + "=" + name + ";");commentGenerator.addGeneralMethodComment(method, introspectedTable);topLevelClass.addMethod(method);method = new Method();method.setVisibility(JavaVisibility.PUBLIC);method.setReturnType(new FullyQualifiedJavaType(pageClassPath));method.setName("get" + camel);method.addBodyLine("return " + name + ";");commentGenerator.addGeneralMethodComment(method, introspectedTable);topLevelClass.addMethod(method);}/** * This plugin is always valid - no properties are required */public boolean validate(List<String> warnings){return true;}}

生成xml的插件内容使用,请参考:
http://blog.csdn.net/xzknet/article/details/44158009