新增 DefaultBeanResultMap

README.md

@@ -1,3 +1,6 @@
 # SimpleJDBC
 对 JDBC 的简单封装。
-之前遇到的一个老项目，没有引入任何 ORM 框架，使用的 JDK7 明明支持泛型，所依赖的 spring-jdbc 居然是没有泛型的远古版本，该项目又不允许随意添加依赖，对数据库的操作几乎都在写原生 JDBC。故自己写了几个工具类，对 JDBC 进行简单封装，有了这东西的雏形。
+
+之前遇到的一个老项目，没有引入任何 ORM 框架，使用的 JDK7 明明支持泛型，所依赖的 spring-jdbc 居然是没有泛型的远古版本，该项目又不允许随意添加依赖，对数据库的操作几乎都在写原生 JDBC。故自己写了几个工具类，对 JDBC 进行简单封装，后来逐渐改进完善。
+
+本项目不比成熟的工具，如若使用请自行承担风险。建议仅作为 JDBC 的学习参考。

src/main/java/xyz/zhouxy/jdbc/DefaultBeanResultMap.java

@@ -0,0 +1,88 @@
+package xyz.zhouxy.jdbc;
+
+import java.beans.BeanInfo;
+import java.beans.IntrospectionException;
+import java.beans.Introspector;
+import java.beans.PropertyDescriptor;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import javax.annotation.Nullable;
+
+public class DefaultBeanResultMap<T> implements ResultMap<T> {
+
+    private final Constructor<T> constructor;
+    private final Map<String, PropertyDescriptor> colPropertyMap;
+
+    private DefaultBeanResultMap(Constructor<T> constructor, Map<String, PropertyDescriptor> colPropertyMap) {
+        this.constructor = constructor;
+        this.colPropertyMap = colPropertyMap;
+    }
+
+    public static <T> DefaultBeanResultMap<T> of(Class<T> beanType) throws SQLException {
+        return of(beanType, null);
+    }
+
+    public static <T> DefaultBeanResultMap<T> of(Class<T> beanType, @Nullable Map<String, String> propertyColMap)
+            throws SQLException {
+        try {
+            BeanInfo beanInfo = Introspector.getBeanInfo(beanType);
+            PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
+            Map<String, PropertyDescriptor> colPropertyMap;
+            if (propertyColMap != null && !propertyColMap.isEmpty()) {
+                colPropertyMap = Arrays.stream(propertyDescriptors)
+                        .collect(Collectors.toMap(p -> {
+                            String propertyName = p.getName();
+                            String colName = propertyColMap.get(propertyName);
+                            return colName != null ? colName : propertyName;
+                        }, Function.identity(), (a, b) -> b));
+            }
+            else {
+                colPropertyMap = Arrays.stream(propertyDescriptors)
+                        .collect(Collectors.toMap(PropertyDescriptor::getName, Function.identity(), (a, b) -> b));
+            }
+
+            Constructor<T> constructor = beanType.getDeclaredConstructor();
+            constructor.setAccessible(true); // NOSONAR
+            return new DefaultBeanResultMap<>(constructor, colPropertyMap);
+        }
+        catch (IntrospectionException e) {
+            throw new SQLException("There is an exception occurs during introspection.", e);
+        }
+        catch (NoSuchMethodException e) {
+            throw new SQLException("Could not find a no-args constructor in " + beanType.getName(), e);
+        }
+    }
+
+    @Override
+    public T map(ResultSet rs, int rowNumber) throws SQLException {
+        try {
+            T newInstance = this.constructor.newInstance();
+            ResultSetMetaData metaData = rs.getMetaData();
+            for (int i = 1; i <= metaData.getColumnCount(); i++) {
+                String colName = metaData.getColumnName(i);
+                PropertyDescriptor propertyDescriptor = this.colPropertyMap.get(colName);
+                if (propertyDescriptor != null) {
+                    Method setter = propertyDescriptor.getWriteMethod();
+                    if (setter != null) {
+                        Class<?> propertyType = propertyDescriptor.getPropertyType();
+                        setter.setAccessible(true); // NOSONAR
+                        setter.invoke(newInstance, rs.getObject(colName, propertyType));
+                    }
+                }
+            }
+            return newInstance;
+        }
+        catch (IllegalAccessException | InstantiationException | InvocationTargetException e) {
+            throw new SQLException(e);
+        }
+    }
+}

src/main/java/xyz/zhouxy/jdbc/ResultMap.java

@@ -37,7 +37,6 @@ public interface ResultMap<T> {
         return result;
     };
 
-
     public static final ResultMap<DbRecord> recordResultMap = (rs, rowNumber) -> {
         DbRecord result = new DbRecord();
         ResultSetMetaData metaData = rs.getMetaData();
@@ -48,4 +47,13 @@ public interface ResultMap<T> {
         }
         return result;
     };
+
+    public static <T> ResultMap<T> beanResultMap(Class<T> beanType) throws SQLException {
+        return DefaultBeanResultMap.of(beanType);
+    }
+
+    public static <T> ResultMap<T> beanResultMap(Class<T> beanType, Map<String, String> propertyColMap)
+            throws SQLException {
+        return DefaultBeanResultMap.of(beanType, propertyColMap);
+    }
 }

src/test/java/xyz/zhouxy/jdbc/test/SimpleJdbcTemplateTests.java

@@ -1,4 +1,4 @@
-package xyz.zhouxy.jdbc;
+package xyz.zhouxy.jdbc.test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
@@ -6,6 +6,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import static xyz.zhouxy.jdbc.ParamBuilder.*;
 import static xyz.zhouxy.plusone.commons.sql.JdbcSql.IN;
 
+import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
@@ -21,10 +22,15 @@ import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
 
+import xyz.zhouxy.jdbc.DbRecord;
+import xyz.zhouxy.jdbc.DefaultBeanResultMap;
+import xyz.zhouxy.jdbc.ResultMap;
+import xyz.zhouxy.jdbc.SimpleJdbcTemplate;
 import xyz.zhouxy.jdbc.SimpleJdbcTemplate.JdbcExecutor;
 import xyz.zhouxy.plusone.commons.sql.SQL;
 import xyz.zhouxy.plusone.commons.util.ArrayTools;
@@ -53,20 +59,19 @@ class SimpleJdbcTemplateTests {
 
     @Test
     void testQuery() throws SQLException {
-        Object[] ids = buildParams("501533", "501554", "544599");
+        Object[] ids = buildParams(22915, 22916, 22917, 22918, 22919, 22920, 22921);
         String sql = SQL.newJdbcSql()
                 .SELECT("*")
                 .FROM("test_table")
                 .WHERE(IN("id", ids))
                 .toString();
         log.info(sql);
-        List<DbRecord> rs = jdbcTemplate
+        List<DbRecord> rs = jdbcTemplate.queryToRecordList(sql, ids);
-                .queryToRecordList(sql, ids);
         assertNotNull(rs);
         for (DbRecord baseEntity : rs) {
             // log.info("id: {}", baseEntity.getValueAsString("id")); // NOSONAR
             log.info(baseEntity.toString());
-            assertEquals(Optional.empty(), baseEntity.getValueAsString("updated_by"));
+            assertTrue(baseEntity.getValueAsString("username").isPresent());
         }
     }
 
@@ -218,4 +223,58 @@ class SimpleJdbcTemplateTests {
             throw e;
         }
     }
+
+    @Test
+    void testBean() throws Exception {
+        Optional<TestBean> t = jdbcTemplate.queryFirst(
+                "SELECT * FROM test_table WHERE id = ?",
+                buildParams(22915),
+                ResultMap.beanResultMap(TestBean.class, ImmutableMap.of("usageDate", "usage_date", "usageDuration", "usage_duration")));
+        log.info("t: {}", t);
+    }
+}
+
+class TestBean {
+    Long id;
+    String username;
+    LocalDate usageDate;
+    Long usageDuration;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public LocalDate getUsageDate() {
+        return usageDate;
+    }
+
+    public void setUsageDate(LocalDate usageDate) {
+        this.usageDate = usageDate;
+    }
+
+    public Long getUsageDuration() {
+        return usageDuration;
+    }
+
+    public void setUsageDuration(Long usageDuration) {
+        this.usageDuration = usageDuration;
+    }
+
+    @Override
+    public String toString() {
+        return "TestBean [id=" + id + ", username=" + username + ", usageDate=" + usageDate + ", usageDuration="
+                + usageDuration + "]";
+    }
 }