发现要坚持写博客真的是一件很困难的事情，各种原因都会导致顾不上博客。本来打算写自己动手实现orm，看看时间，还是先实现一个动态sql，下次有时间再补上orm完整的实现吧。
用过mybatis的人，估计对动态sql都不陌生，如果没有用过，就当看看热闹吧。我第一次接触mysql是在大四的时候，当时就觉得动态sql这东西很牛，很灵活，一直想搞明白怎么实现的，尽管当时已经能够写ioc，mvc和简单的orm框架(仿mybaits但是没有动态sql部分)，但是仍然找不到mybatis核心的动态sql到底在哪实现的，怎么实现的，可能是那些代码太绕根本没法看懂，直到目前，我都没有勇气去看mybatis的动态sql部分，大概是天生对算法有莫名其妙的敬畏吧。
几年前因为想做一个配置平台，想用解析型语言替代java的实现，可以让配置人员在页面上方便的编写少量代码实现复杂的业务逻辑（包括数据库操作）。当时java已经有js解析引擎，但是大多数人都说效率太低，不知道我发什么疯就想到自己实现一个解析语言。不过实现自己的语言也是我一直的梦想，解析语言相对编译型语言入手简单，于是我就果断动手了，写完才知道，其实自己的实现估计还没有当时的js引擎效率高，那时的我真的是很年轻很简单。今天谈到的动态sql实现其实就是受到那时候解析语言的启发。
废话不多说直接开始聊动态sql，请看下面例子，先声明这里的例子并不是一个正确的sql的写法，只是想写一个尽量复杂的嵌套结构，如果把这种复杂的情况实现了，那么简单一点的就更加不在话下了。
delete from pl_pagewidget<if test="widgetcodes != null"> where pagewidgetcode in <foreach collection="widgetcodes" item="item" index="index" open="(" separator="," close=")"> <if test="index == 0"> #{item} </if> <foreach collection="bs" item="b" index="index1" open="(" separator="," close=")"> #{b} </foreach> </foreach></if><if test="a != null"> and a = #{a}</if>要实现解析出上面例子的sql，首先一个难点类似是test属性里的条件怎么判断真假，不过这个难点在struts2中学到的ognl表达式面前就比较小儿科了。不知道有么有朋友遇到过一个比较奇葩的现象，就是有时候明明在mybatis动态sql中写如下表达式，但是当n=0的时候居然是满足条件的也就是test里的值是false，0居然不能满足这个表达式的条件，这里就是ognl库的原因了。没办法它就是这么玩的，当成特殊情况记住就可以了
test="n != null and n !=''"
ognl表达式使用很方便如下
import java.util.HashMap;import java.util.Map;import ognl.Ognl;public class OgnlTest { //输出结果:false public static void main(String[] args) throws Exception { String con1 = "n != null and n != ''"; Map<String,Object> root = new HashMap<>(); root.put("n", 0); System.out.println(Ognl.getValue(con1,root)); }}要实现解析上面例子的sql，第二个难点就是虽然这个sql披上一层xml的皮就是一个标准的sql，如下
<sql> delete from pl_pagewidget <if test="widgetcodes != null"> where pagewidgetcode in <foreach collection="widgetcodes" item="item" index="index" open="(" separator="," close=")"> <if test="index == 0"> #{item} </if> <foreach collection="bs" item="b" index="index1" open="(" separator="," close=")"> #{b} </foreach> </foreach> </if> <if test="a != null"> and a = #{a} </if></sql>但是要解析上面的xml和我们平时不一样，这个xml是标签和文本混合的，正常我们开发中应该很少会用到解析这种xml。不过我们常用的解析xml的工具dom4j其实可以很好的解析这种sql，只不过很少可能用到。Element类的content()方法就可以返回一个Node的集合，再通过遍历这个集合，判断每个Node的类型就可以了。解决了这两个重点，只需要加上一点技巧就可以解析这种动态sql了。
我用到的技巧是根据java语法格式得到的启发。比如java中有局部变量和全局变量，不考虑引用传递这种情况，如果全局变量int i = 1；方法里面传入这个全局变量，然后在方法里面修改，在方法里面看到的是改变后的值，但是在方法外面看到的仍然是1。这个现象其实学过java应该都知道。还有就是当方法调用的时候，方法里面可以看到全局变量，也可以看到局部变量，方法调用结束后局部变量会被清空释放(看垃圾搜集器高兴)。介绍了这些直接上代码了
import java.io.StringReader;import java.text.SimpleDateFormat;import java.util.Arrays;import java.util.Date;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.regex.Matcher;import java.util.regex.Pattern;import org.apache.commons.collections.MapUtils;import org.apache.commons.lang.StringUtils;import org.dom4j.Document;import org.dom4j.Element;import org.dom4j.Node;import org.dom4j.Text;import org.dom4j.io.SAXReader;import com.rd.sql.Attrs;import com.rd.sql.BaseNode;import com.rd.sql.NodeFactory;public class SqlParser { private Map<String,Object> currParams = new HashMap<String,Object>(); /** delete from pl_pagewidget <if test="widgetcodes != null"> where pagewidgetcode in <foreach collection="widgetcodes" item="item" index="index" open="(" separator="," close=")"> <if test="index == 0"> #{item} </if> <foreach collection="bs" item="b" index="index1" open="(" separator="," close=")"> #{b} </foreach> </foreach> </if> <if test="a != null"> and a = #{a} </if> */ public static void main(String[] args) throws Exception { Map<String, Object> map = new HashMap<String, Object>(); map.put("widgetcodes", Arrays.asList("1", "2")); map.put("bs", Arrays.asList("3", "4")); map.put("a", 1); SqlParser parser = new SqlParser(); System.out .println(parser.parser("delete from pl_pagewidget/n" + "/t<if test=/"widgetcodes != null/">/n" + "/t/twhere pagewidgetcode in/n" + "/t/t<foreach collection=/"widgetcodes/" item=/"item/" index=/"index/" open=/"(/" separator=/",/" close=/")/">/n" + "/t/t <if test=/"index == 0/">/n" + "/t/t #{item}/n" + "/t/t </if>/n" + "/t/t <foreach collection=/"bs/" item=/"b/" index=/"index1/" open=/"(/" separator=/",/" close=/")/">/n" + "/t/t/t#{b}/n" + "/t/t </foreach>/n" + "/t/t</foreach>/n" + "/t</if>/n" + "/t<if test=/"a != null/">/n" + "/t/tand a = #{a}/n" + "/t</if>/n", map)); System.out.println(parser.getParams()); } public String parser(String xml, Map<String, Object> params) throws Exception { // xml = "<?xml version=/"1.0/" encoding=/"UTF-8/"?>"+xml; //给输入的动态sql套一层xml标签 xml = "<sql>"+xml+"</sql>"; SAXReader reader = new SAXReader(false); Document document = reader.read(new StringReader(xml)); Element element = document.getRootElement(); Map<String, Object> currParams = new HashMap<String, Object>(); StringBuilder sb = new StringBuilder(); //开始解析 parserElement(element, currParams, params, sb); return sb.toString(); } /** * 使用递归解析动态sql * @param ele1 待解析的xml标签 * @param currParams * @param globalParams * @param sb * @throws Exception */ private void parserElement(Element ele1, Map<String, Object> currParams, Map<String, Object> globalParams, StringBuilder sb) throws Exception { // 解析一个节点，比如解析到了一个if节点，假如test判断为true这里就返回true TempVal val = parserOneElement(currParams, globalParams, ele1, sb); //得到解析的这个节点的抽象节点对象 BaseNode node = val.getNode(); /** * 实际上这句之上的语句只是解析了xml的标签，并没有解析标签里的内容，这里 * 表示要解析内容之前，如果有前置操作做一点前置操作 */ node.pre(currParams, globalParams, ele1, sb); //判断是否还需要解析节点里的内容，例如if节点test结果为true boolean flag = val.isContinue(); // 得到该节点下的所有子节点的集合，包含普通文本 List<Node> nodes = ele1.content(); if (flag && !nodes.isEmpty()) { /** * 这里表示要进一步解析节点里的内容了，可以把节点类比成一个方法的外壳 * 里面的内容类比成方法里的具体语句，开始解析节点的内容之前 * 先创建本节点下的局部参数的容器，最方便当然是map */ Map<String, Object> params = new HashMap<String, Object>(); /** * 把外面传进来的局部参数，直接放入容器，由于本例中参数都是常用数据类型 * 不会存在引用类型所以，这里相当于是一个copy，为了不影响外面传入的对象 * 可以类比方法调用传入参数的情况 */ params.putAll(currParams); //循环所有子节点 for (int i = 0; i < nodes.size();) { Node n = nodes.get(i); //如果节点是普通文本 if (n instanceof Text) { String text = ((Text) n).getStringValue(); if (StringUtils.isNotEmpty(text.trim())) { //处理一下文本，如处理#{xx},直接替换${yy}为真实传入的值 sb.append(handText(text, params,globalParams)); } i++; } else if (n instanceof Element) { Element e1 = (Element) n; // 递归解析xml子元素 parserElement(e1, params, globalParams, sb); // 如果循环标志不为true则解析下一个标签 // 这里表示需要重复解析这个循环标签，则i不变,反之继续处理下一个元素 boolean while_flag = MapUtils.getBoolean(params, Attrs.WHILE_FLAG, false); if (!while_flag || !NodeFactory.isWhile(n.getName()) || e1.attributeValue(Attrs.INDEX) == null || !e1.attributeValue(Attrs.INDEX).equals( params.get(Attrs.WHILE_INDEX))) { i++; } } } //节点处理之后做一些啥事 node.after(currParams, globalParams, ele1, sb); // 回收当前作用域参数 params.clear(); params = null; } } /** * 处理文本替换掉#{item}这种参数 * @param str * @param params * @return * @throws Exception */ private String handText(String str, Map<String, Object> params,Map<String, Object> globalParams) throws Exception { //获取foreach这种标签中用于记录循环的变量 String indexStr = MapUtils.getString(params, Attrs.WHILE_INDEX); Integer index = null; if(StringUtils.isNotEmpty(indexStr)) { index = MapUtils.getInteger(params, indexStr); } //匹配#{a}这种参数 String reg1 = "(#//{)(//w+)(//})"; //匹配${a}这种参数 String reg2 = "(//$//{)(//w+)(//})"; Pattern p1 = Pattern.compile(reg1); Matcher m1 = p1.matcher(str); Pattern p2 = Pattern.compile(reg2); Matcher m2 = p2.matcher(str); String whileList = MapUtils.getString(params, Attrs.WHILE_LIST); Map<String,Object> allParams = getAllParams(params, globalParams); while(m1.find()) { String tmpKey = m1.group(2); String key = whileList == null?tmpKey:(whileList+"_"+tmpKey); key = index == null?key:(key+index); String reKey = "#{"+key+"}"; //如果在foreach类似的循环里，可能需要将参数#{xx}替换成#{xx_0},#{xx_1} str = str.replace(m1.group(0), reKey); currParams.put(key, allParams.get(tmpKey)); } while(m2.find()) { String tmpKey = m2.group(2); Object value = allParams.get(tmpKey); if(value != null) { str = str.replace(m2.group(0), getValue(value)); } } return str; } private String getValue(Object value) { String result = ""; if(value instanceof Date) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); result = sdf.format((Date)value); } else { result = String.valueOf(value); } return result; } private Map<String, Object> getAllParams(Map<String, Object> currParams, Map<String, Object> globalParams) { Map<String,Object> allParams = new HashMap<String,Object>(); allParams.putAll(globalParams); allParams.putAll(currParams); return allParams; } // 解析一个xml元素 private TempVal parserOneElement(Map<String, Object> currParams, Map<String, Object> globalParams, Element ele, StringBuilder sb) throws Exception { //获取xml标签名 String eleName = ele.getName(); //解析一个节点后是否继续，如遇到if这种节点，就需要判断test里是否为空 boolean isContinue = false; //声明一个抽象节点 BaseNode node = null; if (StringUtils.isNotEmpty(eleName)) { //使用节点工厂根据节点名得到一个节点对象比如是if节点还是foreach节点 node = NodeFactory.create(eleName); //解析一下这个节点，返回是否还需要解析节点里的内容 isContinue = node.parse(currParams, globalParams, ele, sb); } return new TempVal(isContinue, ele, node); } public Map<String, Object> getParams() { return currParams; } /** * 封装一个xml元素被解析后的结果 * @author rongdi */ final static class TempVal { private boolean isContinue; private Element ele; private BaseNode node; public TempVal(boolean isContinue, Element ele, BaseNode node) { this.isContinue = isContinue; this.ele = ele; this.node = node; } public boolean isContinue() { return isContinue; } public void setContinue(boolean isContinue) { this.isContinue = isContinue; } public Element getEle() { return ele; } public void setEle(Element ele) { this.ele = ele; } public BaseNode getNode() { return node; } public void setNode(BaseNode node) { this.node = node; } }}import org.dom4j.Element;import java.util.HashMap;import java.util.Map;/** * 抽象节点 * @author rongdi */public abstract class BaseNode { public abstract boolean parse(Map<String, Object> currParams, Map<String, Object> globalParams, Element ele,StringBuilder sb) throws Exception; public void pre(Map<String, Object> currParams,Map<String, Object> globalParams,Element ele,StringBuilder sb) throws Exception { } public void after(Map<String, Object> currParams,Map<String, Object> globalParams,Element ele,StringBuilder sb) throws Exception { } protected Map<String, Object> getAllParams(Map<String, Object> currParams, Map<String, Object> globalParams) { Map<String,Object> allParams = new HashMap<String,Object>(); allParams.putAll(globalParams); allParams.putAll(currParams); return allParams; }}import java.util.Map;import ognl.Ognl;import org.apache.commons.lang.StringUtils;import org.dom4j.Element;/** * if节点 * @author rongdi */public class IfNode extends BaseNode{ @Override public boolean parse(Map<String, Object> currParams, Map<String, Object> globalParams, Element ele,StringBuilder sb) throws Exception { //得到if节点的test属性 String testStr = ele.attributeValue("test"); boolean test = false; try { if(StringUtils.isNotEmpty(testStr)) { //合并全局变量和局部变量 Map<String, Object> allParams = getAllParams(currParams,globalParams); //使用ognl判断true或者false test = (Boolean) Ognl.getValue(testStr,allParams); } } catch (Exception e) { e.printStackTrace(); throw new Exception("判断操作参数"+testStr+"不合法"); } if(ele.content() != null && ele.content().size()==0) { test = true; } return test; }}import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.Set;import ognl.Ognl;import org.apache.commons.collections.MapUtils;import org.apache.commons.lang.StringUtils;import org.dom4j.Element;/** foreach节点属性如下 collection 需要遍历的集合 item 遍历集合后每个元素存放的变量 index 遍历集合的索引数如0,1,2... separator 遍历后以指定分隔符拼接 open 遍历后拼接开始的符号如 ( close 遍历后拼接结束的符号如 ) */public class ForeachNode extends BaseNode { @Override public boolean parse(Map<String, Object> currParams, Map<String, Object> globalParams, Element ele, StringBuilder sb) throws Exception { String conditionStr = null; String collectionStr = ele.attributeValue("collection"); String itemStr = ele.attributeValue("item"); String index = ele.attributeValue("index"); String separatorStr = ele.attributeValue("separator"); String openStr = ele.attributeValue("open"); String closeStr = ele.attributeValue("close"); if(StringUtils.isEmpty(index)) { index = "index"; } if(StringUtils.isEmpty(separatorStr)) { separatorStr = ","; } if(StringUtils.isNotEmpty(openStr)) { currParams.put(Attrs.WHILE_OPEN,openStr); } if(StringUtils.isNotEmpty(closeStr)) { currParams.put(Attrs.WHILE_CLOSE,closeStr); } if(StringUtils.isNotEmpty(collectionStr)) { currParams.put(Attrs.WHILE_LIST,collectionStr); } currParams.put(Attrs.WHILE_SEPARATOR,separatorStr); if(index != null) { /** * 如果局部变量中存在当前循环变量的值，就表示已经不是第一次进入循环标签了，移除掉开始标记 * 并将局部变量值加1 */ if(currParams.get(index) != null) { currParams.remove(Attrs.WHILE_START); currParams.put(index+"_", (Integer)currParams.get(index+"_") + 1); } else { //第一次进入循环标签内 currParams.put(Attrs.WHILE_START,true); currParams.put(index+"_", 0); } currParams.put(index, (Integer)currParams.get(index+"_")); } boolean condition = true; Map<String, Object> allParams = getAllParams(currParams,globalParams); Object collection = null; if(StringUtils.isNotEmpty(collectionStr)) { //得到待循环的集合 collection = Ognl.getValue(collectionStr,allParams); //如果集合属性不为空，但是条件为null则默认加上一个边界条件 if(StringUtils.isEmpty(conditionStr)) { //这里只是用集合演示一下，也可以再加上数组，只不过改成.length而已 if(collection instanceof List) { conditionStr = index+"_<"+collectionStr+".size()"; } else if(collection instanceof Map){ Map map = (Map)collection; Set set = map.entrySet(); List list = new ArrayList(set); allParams.put("_list_", list); conditionStr = index+"_<_list_"+".size()"; } } } currParams.remove(Attrs.WHILE_END); if(StringUtils.isNotEmpty(conditionStr)) { //计算条件的值 condition = (Boolean)Ognl.getValue(conditionStr,allParams); Map<String,Object> tempMap = new HashMap<>(); tempMap.putAll(allParams); tempMap.put(index+"_",(Integer)currParams.get(index+"_") + 1); currParams.put(Attrs.WHILE_END,!(Boolean)Ognl.getValue(conditionStr,tempMap)); } boolean flag = true; currParams.put(Attrs.WHILE_INDEX, index); currParams.put(Attrs.WHILE_FLAG, true); if(condition) { try { if(StringUtils.isNotEmpty(itemStr) && StringUtils.isNotEmpty(collectionStr)) { Object value = null; int idx = Integer.parseInt(currParams.get(index+"_").toString()); if(collection instanceof List) { value = ((List)collection).get(idx); currParams.put(itemStr, value); } else if(collection instanceof Map){ Map map = (Map)collection; Set<Map.Entry<String,Object>> set = map.entrySet(); List<Map.Entry<String,Object>> list = new ArrayList(set); currParams.put(itemStr, list.get(idx).getValue()); currParams.put(index, list.get(idx).getKey()); } } } catch (Exception e) { throw new Exception("从集合或者映射取值"+currParams.get(index)+"错误"+e.getMessage()); } } else { flag = false; destroyVars(currParams, index, itemStr); } return flag; } /** * 如果是第一次进入循环标签，则拼上open的内容 */ @Override public void pre(Map<String, Object> currParams, Map<String, Object> globalParams, Element ele, StringBuilder sb) throws Exception { super.pre(currParams, globalParams, ele, sb); boolean start = MapUtils.getBoolean(currParams,Attrs.WHILE_START,false); if(start) { String open = MapUtils.getString(currParams,Attrs.WHILE_OPEN); sb.append(open); } } /** * 如果是最后进入循环标签，则最后拼上close的内容 */ @Override public void after(Map<String, Object> currParams, Map<String, Object> globalParams, Element ele, StringBuilder sb) throws Exception { super.after(currParams, globalParams, ele, sb); boolean end = MapUtils.getBoolean(currParams,Attrs.WHILE_END,false); String separator = MapUtils.getString(currParams,Attrs.WHILE_SEPARATOR); if(!end && StringUtils.isNotEmpty(separator)) { sb.append(separator); } if(end) { String close = MapUtils.getString(currParams,Attrs.WHILE_CLOSE); if(sb.toString().endsWith(separator)) { sb.deleteCharAt(sb.length() - 1); } sb.append(close); } } //释放临时变量 private void destroyVars(Map<String, Object> currParams, String index,String varStr) { currParams.remove(Attrs.WHILE_INDEX); currParams.remove(Attrs.WHILE_FLAG); currParams.remove(Attrs.WHILE_SEPARATOR); currParams.remove(Attrs.WHILE_START); currParams.remove(Attrs.WHILE_END); currParams.remove(Attrs.WHILE_LIST); }} import org.dom4j.Element;import java.util.Map;public class SqlNode extends BaseNode{ @Override public boolean parse(Map<String, Object> currParams, Map<String, Object> globalParams, Element ele,StringBuilder sb) throws Exception { return true; }}import java.util.Arrays;import java.util.List;import java.util.Map;import java.util.concurrent.ConcurrentHashMap;/** * 节点工厂 */public class NodeFactory { private static Map<String,BaseNode> nodeMap = new ConcurrentHashMap<String,BaseNode>(); private final static List<String> whileList = Arrays.asList("foreach"); static { nodeMap.put("if", new IfNode()); nodeMap.put("sql", new SqlNode()); nodeMap.put("foreach", new ForeachNode()); } public static boolean isWhile(String elementName) { return whileList.contains(elementName); } public static void addNode(String nodeName,BaseNode node) { nodeMap.put(nodeName, node); } public static BaseNode create(String nodeName) { return nodeMap.get(nodeName); } }/** * 各种标记 * @author rongdi */public class Attrs { public final static String TRANSACTIONAL = "transactional"; public final static String WHILE_START = "while-start"; public final static String WHILE_END = "while-end"; public final static String WHILE_OPEN = "while-open"; public final static String WHILE_CLOSE = "while-close"; public final static String WHILE_SEPARATOR = "while-separator"; public final static String WHILE_INDEX = "while-index"; public final static String WHILE_FLAG = "while-flag"; public final static String WHILE_LIST = "while-list"; public final static String WHEN_FLAG = "when-flag"; public static final String PROCESS_VAR = "process-var"; public final static String RESULT_FLAG = "result-flag"; public final static String RETURN_FLAG = "return-flag"; public final static String CONSOLE_VAR= "console-var"; public final static String DO = "do"; public final static String INDEX = "index"; public final static String CONDITION = "condition"; public final static String NAME= "name"; public final static String VALUE= "value"; public static final String TYPE = "type"; public static final String FORMAT = "format"; public static final String IF = "if"; public static final String ELSE = "else"; public final static String FILE= "file"; public static final String DATE = "date"; public static final String NOW = "now"; public static final String DECIMAL = "decimal"; public static final String ID = "id"; public static final String PARAMS = "params"; public static final String TARGET = "target"; public static final String SINGLE = "single"; public static final String PAGING = "paging"; public static final String DESC = "desc"; public static final String BREAK = "break"; public static final String CONTINUE = "continue"; public static final String COLLECTION = "collection"; public static final String VAR = "var"; public static final String EXECUTOR = "executor-1"; public static final String ROLLBACK_FLAG = "rollback-flag"; public static final String SERVICE = "service"; public static final String REF = "ref"; public static final String BIZS = "bizs"; public static final String TITLES = "titles"; public static final String COLUMNS = "columns"; public static final String CURRUSER = "currUser"; public static final String CURRPERM = "currPerm"; public static final String TASK_EXECUTOR = "taskExecutor"; public static final String DELIMITER = "delimiter"; public static final String OPERNAME = "operName"; } currParams.remove(varStr); currParams.remove(index); currParams.remove(index+"_"); }}附上pom文件
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.rd</groupId> <artifactId>parser</artifactId> <packaging>jar</packaging> <version>1.0-SNAPSHOT</version> <name>myparser</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>dom4j</groupId> <artifactId>dom4j</artifactId> <version>1.6.1</version> </dependency> <dependency> <groupId>opensymphony</groupId> <artifactId>ognl</artifactId> <version>2.6.11</version> </dependency> <dependency> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> <version>3.2.1</version> </dependency> <dependency> <groupId>commons-lang</groupId> <artifactId>commons-lang</artifactId> <version>2.6</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> </dependencies> <build> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> <resource> <directory>src/main/resources</directory> <includes> <include>**/*</include> </includes> </resource> </resources> <testResources> <testResource> <directory>${project.basedir}/src/test/java</directory> </testResource> <testResource> <directory>${project.basedir}/src/test/resources</directory> </testResource> </testResources> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.1</version> <configuration> <source>1.8</source> <target>1.8</target> <encoding>UTF-8</encoding> </configuration> </plugin> </plugins> </build></project>以上这篇自己动手实现mybatis动态sql的方法就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持武林网。