foreach标签实现

FuriousPws002 · Apr 17, 2024 · 083c167 · 083c167
1 parent b1af0bc
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Showing 11 changed files with 284 additions and 3 deletions.
diff --git a/README.md b/README.md
@@ -7,3 +7,4 @@
 [4.参数绑定](https://github.com/FuriousPws002/mini-mybatis/wiki/4.%E5%8F%82%E6%95%B0%E7%BB%91%E5%AE%9A "Markdown") <br>
 [5.resultType结果集处理](https://github.com/FuriousPws002/mini-mybatis/wiki/5.resultType%E7%BB%93%E6%9E%9C%E9%9B%86%E5%A4%84%E7%90%86 "Markdown") <br>
 [6.resultMap结果集处理](https://github.com/FuriousPws002/mini-mybatis/wiki/6.resultMap%E7%BB%93%E6%9E%9C%E9%9B%86%E5%A4%84%E7%90%86 "Markdown") <br>
+[7.动态sql](https://github.com/FuriousPws002/mini-mybatis/wiki/7.%E5%8A%A8%E6%80%81sql "Markdown") <br>
diff --git a/src/main/java/org/apache/ibatis/mapping/BoundSql.java b/src/main/java/org/apache/ibatis/mapping/BoundSql.java
@@ -1,6 +1,8 @@
 package org.apache.ibatis.mapping;
 
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * @author furious 2024/4/7
@@ -10,15 +12,21 @@ public class BoundSql {
     private final String sql;
     private final List<ParameterMapping> parameterMappings;
     private final Object parameterObject;
+    private final Map<String, Object> additionalParameters;
 
     public BoundSql(String sql) {
         this(sql, null, null);
     }
 
     public BoundSql(String sql, List<ParameterMapping> parameterMappings, Object parameterObject) {
+        this(sql, parameterMappings, parameterObject, new HashMap<>());
+    }
+
+    public BoundSql(String sql, List<ParameterMapping> parameterMappings, Object parameterObject, Map<String, Object> additionalParameters) {
         this.sql = sql;
         this.parameterMappings = parameterMappings;
         this.parameterObject = parameterObject;
+        this.additionalParameters = additionalParameters;
     }
 
     public List<ParameterMapping> getParameterMappings() {
@@ -32,4 +40,20 @@ public Object getParameterObject() {
     public String getSql() {
         return this.sql;
     }
+
+    public void setAdditionalParameter(String key, Object value) {
+        additionalParameters.put(key, value);
+    }
+
+    public Object getAdditionalParameter(String key) {
+        return additionalParameters.get(key);
+    }
+
+    public boolean hasAdditionalParameter(String key) {
+        return additionalParameters.containsKey(key);
+    }
+
+    public Map<String, Object> getAdditionalParameters() {
+        return additionalParameters;
+    }
 }
diff --git a/src/main/java/org/apache/ibatis/mapping/MappedStatement.java b/src/main/java/org/apache/ibatis/mapping/MappedStatement.java
@@ -28,7 +28,7 @@ public Configuration getConfiguration() {
 
     public BoundSql getBoundSql(Object parameterObject) {
         BoundSql boundSql = sqlSource.getBoundSql(parameterObject);
-        return new BoundSql(boundSql.getSql(),boundSql.getParameterMappings(),parameterObject);
+        return new BoundSql(boundSql.getSql(), boundSql.getParameterMappings(), parameterObject, boundSql.getAdditionalParameters());
     }
 
     public ResultMap getResultMap() {

diff --git a/src/main/java/org/apache/ibatis/scripting/defaults/DefaultParameterHandler.java b/src/main/java/org/apache/ibatis/scripting/defaults/DefaultParameterHandler.java
@@ -47,7 +47,9 @@ public void setParameters(PreparedStatement ps) throws SQLException {
             ParameterMapping parameterMapping = parameterMappings.get(i);
             Object value;
             String propertyName = parameterMapping.getProperty();
-            if (Objects.isNull(parameterObject)) {
+            if (boundSql.hasAdditionalParameter(propertyName)) {
+                value = boundSql.getAdditionalParameter(propertyName);
+            }else if (Objects.isNull(parameterObject)) {
                 value = null;
             } else if (configuration.getTypeHandlerRegistry().hasTypeHandler(parameterObject.getClass())) {
                 value = parameterObject;

diff --git a/src/main/java/org/apache/ibatis/scripting/xmltags/DynamicContext.java b/src/main/java/org/apache/ibatis/scripting/xmltags/DynamicContext.java
@@ -1,5 +1,7 @@
 package org.apache.ibatis.scripting.xmltags;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.StringJoiner;
 
 /**
@@ -9,6 +11,7 @@ public class DynamicContext {
 
     private final StringJoiner sqlBuilder = new StringJoiner(" ");
     private Object parameterObject;
+    private final Map<String, Object> bindings = new HashMap<>();
 
     public DynamicContext() {
     }
@@ -32,4 +35,12 @@ public Object getParameterObject() {
     public void setParameterObject(Object parameterObject) {
         this.parameterObject = parameterObject;
     }
+
+    public Map<String, Object> getBindings() {
+        return bindings;
+    }
+
+    public void bind(String key, Object value) {
+        bindings.put(key, value);
+    }
 }
diff --git a/src/main/java/org/apache/ibatis/scripting/xmltags/DynamicSqlSource.java b/src/main/java/org/apache/ibatis/scripting/xmltags/DynamicSqlSource.java
@@ -25,6 +25,8 @@ public BoundSql getBoundSql(Object parameterObject) {
         SqlSourceBuilder sqlSourceParser = new SqlSourceBuilder(configuration);
         Class<?> parameterType = parameterObject == null ? Object.class : parameterObject.getClass();
         SqlSource sqlSource = sqlSourceParser.parse(context.getSql(), parameterType);
-        return sqlSource.getBoundSql(parameterObject);
+        BoundSql boundSql = sqlSource.getBoundSql(parameterObject);
+        context.getBindings().forEach(boundSql::setAdditionalParameter);
+        return boundSql;
     }
 }
diff --git a/src/main/java/org/apache/ibatis/scripting/xmltags/ForeachSqlNode.java b/src/main/java/org/apache/ibatis/scripting/xmltags/ForeachSqlNode.java
@@ -0,0 +1,157 @@
+package org.apache.ibatis.scripting.xmltags;
+
+import java.util.Map;
+import java.util.Objects;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.ibatis.parsing.GenericTokenParser;
+
+import ognl.Ognl;
+
+/**
+ * @author furious 2024/4/17
+ */
+public class ForeachSqlNode implements SqlNode {
+
+    public static final String ITEM_PREFIX = ForeachSqlNode.class.getName();
+
+    private final SqlNode contents;
+    private final String collection;
+    private final String item;
+    private final String open;
+    private final String close;
+    private final String separator;
+
+    public ForeachSqlNode(SqlNode contents, String collection, String item, String open, String close, String separator) {
+        this.contents = contents;
+        this.collection = collection;
+        this.item = item;
+        this.open = open;
+        this.close = close;
+        this.separator = separator;
+    }
+
+    @Override
+    @SuppressWarnings("rawtypes")
+    public boolean apply(DynamicContext context) {
+        Iterable<?> iterable = null;
+        try {
+            Object value = Ognl.getValue(Ognl.parseExpression(collection), context.getParameterObject());
+            if (value instanceof Iterable && ((Iterable) value).iterator().hasNext()) {
+                iterable = (Iterable) value;
+            }
+        } catch (Exception e) {
+            return false;
+        }
+        if (Objects.isNull(iterable)) {
+            return true;
+        }
+
+        applyOpen(context);
+        int index = 0;
+        for (Object o : iterable) {
+            DynamicContext oldContext = context;
+            if (index == 0) {
+                context = new SeparatorContext(context, "");
+            } else {
+                context = new SeparatorContext(context, separator);
+            }
+            applyItem(context, o, index);
+            contents.apply(new FilteredDynamicContext(context, item, index));
+            context = oldContext;
+            index++;
+        }
+        applyClose(context);
+        return true;
+    }
+
+    private void applyOpen(DynamicContext context) {
+        if (Objects.nonNull(open)) {
+            context.appendSql(open);
+        }
+    }
+
+    private void applyItem(DynamicContext context, Object o, int i) {
+        if (Objects.nonNull(item)) {
+            context.bind(item, o);
+            context.bind(itemizeItem(item, i), o);
+        }
+    }
+
+    private void applyClose(DynamicContext context) {
+        if (Objects.nonNull(close)) {
+            context.appendSql(close);
+        }
+    }
+
+    private static String itemizeItem(String item, int i) {
+        return ITEM_PREFIX + item + "_" + i;
+    }
+
+    private static class SeparatorContext extends DynamicContext {
+
+        private final DynamicContext delegate;
+        private final String separator;
+
+        public SeparatorContext(DynamicContext delegate, String separator) {
+            this.delegate = delegate;
+            this.separator = separator;
+        }
+
+        @Override
+        public Map<String, Object> getBindings() {
+            return delegate.getBindings();
+        }
+
+        @Override
+        public void bind(String name, Object value) {
+            delegate.bind(name, value);
+        }
+
+        @Override
+        public void appendSql(String sql) {
+            if (StringUtils.isNoneBlank(sql)) {
+                delegate.appendSql(separator);
+            }
+            delegate.appendSql(sql);
+        }
+
+        @Override
+        public String getSql() {
+            return delegate.getSql();
+        }
+    }
+
+    private static class FilteredDynamicContext extends DynamicContext {
+        private final DynamicContext delegate;
+        private final String item;
+        private final int index;
+
+        public FilteredDynamicContext(DynamicContext delegate, String item, int index) {
+            this.delegate = delegate;
+            this.item = item;
+            this.index = index;
+        }
+
+        @Override
+        public Map<String, Object> getBindings() {
+            return delegate.getBindings();
+        }
+
+        @Override
+        public void bind(String name, Object value) {
+            delegate.bind(name, value);
+        }
+
+        @Override
+        public String getSql() {
+            return delegate.getSql();
+        }
+
+        @Override
+        public void appendSql(String sql) {
+            GenericTokenParser parser = new GenericTokenParser("#{", "}", content -> "#{" + itemizeItem(item, index) + "}");
+            delegate.appendSql(parser.parse(sql));
+        }
+    }
+}
diff --git a/src/main/java/org/apache/ibatis/scripting/xmltags/XMLScriptBuilder.java b/src/main/java/org/apache/ibatis/scripting/xmltags/XMLScriptBuilder.java
@@ -34,6 +34,7 @@ public XMLScriptBuilder(Configuration configuration, XNode context, Class<?> par
         this.parameterType = parameterType;
         nodeHandlerMap.put("if", new IfHandler());
         nodeHandlerMap.put("trim", new TrimHandler());
+        nodeHandlerMap.put("foreach", new ForeachHandler());
     }
 
     public SqlSource parseScriptNode() {
@@ -96,4 +97,20 @@ public void handleNode(XNode nodeToHandle, List<SqlNode> targetContents) {
             targetContents.add(trim);
         }
     }
+
+    private class ForeachHandler implements NodeHandler {
+
+        @Override
+        public void handleNode(XNode nodeToHandle, List<SqlNode> targetContents) {
+            MixedSqlNode mixedSqlNode = parseDynamicTags(nodeToHandle);
+            String collection = nodeToHandle.getAttribute("collection");
+            String item = nodeToHandle.getAttribute("item");
+            String open = nodeToHandle.getAttribute("open");
+            String close = nodeToHandle.getAttribute("close");
+            String separator = nodeToHandle.getAttribute("separator");
+            ForeachSqlNode forEachSqlNode = new ForeachSqlNode(mixedSqlNode, collection, item, open, close, separator);
+            targetContents.add(forEachSqlNode);
+        }
+    }
+
 }
diff --git a/src/test/java/org/apache/ibatis/dao/UserMapper.java b/src/test/java/org/apache/ibatis/dao/UserMapper.java
@@ -35,4 +35,8 @@ public interface UserMapper {
     List<UserDO> selectResultMap();
 
     List<UserDTO> selectNestedResultMap();
+
+    List<UserDO> listDynamic(@Param("name") String name, @Param("age") Integer age);
+
+    List<UserDO> listForeach(@Param("ids") List<Long> ids);
 }
diff --git a/src/test/java/org/apache/ibatis/session/SqlSessionTest.java b/src/test/java/org/apache/ibatis/session/SqlSessionTest.java
@@ -1,5 +1,6 @@
 package org.apache.ibatis.session;
 
+import java.util.ArrayList;
 import java.util.List;
 
 import org.apache.ibatis.DataSourceBuilderTest;
@@ -127,4 +128,42 @@ public void queryNestedResultMap() {
         Assert.assertNotNull(user.getName());
         Assert.assertNotNull(user.getCarList());
     }
+
+    /**
+     * 动态SQL-包含trim标签和if标签
+     */
+    @Test
+    public void queryDynamicSql() {
+        UserMapper userMapper = getUserMapper();
+        List<UserDO> list1 = userMapper.listDynamic(null, null);
+        Assert.assertNotNull(list1);
+        List<UserDO> list2 = userMapper.listDynamic("Sam", null);
+        Assert.assertNotNull(list2);
+        List<UserDO> list3 = userMapper.listDynamic(null, 20);
+        Assert.assertNotNull(list3);
+        List<UserDO> list4 = userMapper.listDynamic("Sam", 20);
+        Assert.assertNotNull(list4);
+    }
+
+    /**
+     * foreach标签测试
+     */
+    @Test
+    public void queryForeachTag() {
+        UserMapper userMapper = getUserMapper();
+        List<Long> idList = new ArrayList<>();
+        idList.add(1L);
+        idList.add(2L);
+        List<UserDO> list = userMapper.listForeach(idList);
+        Assert.assertNotNull(list);
+    }
+
+    private UserMapper getUserMapper() {
+        Configuration configuration = new Configuration();
+        configuration.setDataSource(DataSourceBuilderTest.build());
+        configuration.addMapper(UserMapper.class);
+        SqlSession sqlSession = new DefaultSqlSession(configuration);
+        return sqlSession.getMapper(UserMapper.class);
+    }
+
 }
diff --git a/src/test/resources/mapper/UserMapper.xml b/src/test/resources/mapper/UserMapper.xml
@@ -53,6 +53,30 @@
         LEFT JOIN car ON relation.car_id = car.id
     </select>
 
+    <select id="listDynamic" resultType="org.apache.ibatis.entity.UserDO">
+        SELECT
+        name,
+        age
+        FROM user
+        <trim prefix="WHERE" prefixOverrides="AND |OR ">
+            <if test="name != null">
+                and name = #{name}
+            </if>
+            <if test="age != null">
+                and age = #{age}
+            </if>
+        </trim>
+    </select>
 
+    <select id="listForeach" resultType="org.apache.ibatis.entity.UserDO">
+        SELECT
+        name,
+        age
+        FROM user
+        WHERE id IN
+        <foreach collection="ids" item="item" open="(" separator="," close=")">
+            #{item}
+        </foreach>
+    </select>
 
 </mapper>