From 2c30de4fae1b686cbcfc048f1449bde14a830fcc Mon Sep 17 00:00:00 2001
From: Looly <loolly@gmail.com>
Date: Thu, 24 Jun 2021 08:26:46 +0800
Subject: [PATCH] add methods

---
 CHANGELOG.md                                  |  1 +
 .../cn/hutool/core/text/csv/CsvWriter.java    | 18 +++++-----
 .../cn/hutool/core/text/csv/CsvUtilTest.java  | 34 ++++---------------
 3 files changed, 18 insertions(+), 35 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index eb0db07f4..b01430849 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 
 ### 🐣新特性
 * 【core   】     增加Convert.toSet方法（issue#I3XFG2@Gitee）
+* 【core   】     CsvWriter增加writeBeans方法（pr#345@Gitee）
 
 ### 🐞Bug修复
 * 【json   】     修复XML转义字符的问题（issue#I3XH09@Gitee）
diff --git a/hutool-core/src/main/java/cn/hutool/core/text/csv/CsvWriter.java b/hutool-core/src/main/java/cn/hutool/core/text/csv/CsvWriter.java
index d55e25b7f..cc2f1778a 100644
--- a/hutool-core/src/main/java/cn/hutool/core/text/csv/CsvWriter.java
+++ b/hutool-core/src/main/java/cn/hutool/core/text/csv/CsvWriter.java
@@ -19,10 +19,8 @@ import java.io.IOException;
 import java.io.Serializable;
 import java.io.Writer;
 import java.nio.charset.Charset;
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
-import java.util.stream.Collectors;
+import java.util.Map;
 
 /**
  * CSV数据写出器
@@ -217,13 +215,17 @@ public final class CsvWriter implements Closeable, Flushable, Serializable {
 	 */
 	public CsvWriter writeBeans(Collection<?> beans) {
 		if (CollUtil.isNotEmpty(beans)) {
-			List<Collection<Object>> res = new ArrayList<>();
+			boolean isFirst = true;
+			Map<String, Object> map;
 			for (Object bean : beans) {
-				res.add(BeanUtil.beanToMap(bean).keySet().stream().map(k -> (Object) k).collect(Collectors.toList()));
-				break;
+				map = BeanUtil.beanToMap(bean);
+				if(isFirst){
+					writeLine(map.keySet().toArray(new String[0]));
+					isFirst = false;
+				}
+				writeLine(Convert.toStrArray(map.values()));
 			}
-			res.addAll(beans.stream().map(bean -> BeanUtil.beanToMap(bean).values()).collect(Collectors.toList()));
-			write(res);
+			flush();
 		}
 		return this;
 	}
diff --git a/hutool-core/src/test/java/cn/hutool/core/text/csv/CsvUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/text/csv/CsvUtilTest.java
index 1763061cd..6f58817c3 100644
--- a/hutool-core/src/test/java/cn/hutool/core/text/csv/CsvUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/text/csv/CsvUtilTest.java
@@ -3,6 +3,7 @@ package cn.hutool.core.text.csv;
 import cn.hutool.core.io.FileUtil;
 import cn.hutool.core.lang.Console;
 import cn.hutool.core.util.CharsetUtil;
+import lombok.Data;
 import org.junit.Assert;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -64,49 +65,27 @@ public class CsvUtilTest {
 	@Test
 	@Ignore
 	public void writeBeansTest() {
+
+		@Data
 		class Student {
 			Integer id;
 			String name;
 			Integer age;
-
-			public Integer getId() {
-				return id;
-			}
-
-			public void setId(Integer id) {
-				this.id = id;
-			}
-
-			public String getName() {
-				return name;
-			}
-
-			public void setName(String name) {
-				this.name = name;
-			}
-
-			public Integer getAge() {
-				return age;
-			}
-
-			public void setAge(Integer age) {
-				this.age = age;
-			}
 		}
+
 		CsvWriter writer = CsvUtil.getWriter("d:/test/testWriteBeans.csv", CharsetUtil.CHARSET_UTF_8);
 		List<Student> students = new ArrayList<>();
 		Student student1 = new Student();
-		Student student2 = new Student();
-		Student student3 = new Student();
-
 		student1.setId(1);
 		student1.setName("张三");
 		student1.setAge(18);
 
+		Student student2 = new Student();
 		student2.setId(2);
 		student2.setName("李四");
 		student2.setAge(22);
 
+		Student student3 = new Student();
 		student3.setId(3);
 		student3.setName("王五");
 		student3.setAge(31);
@@ -115,6 +94,7 @@ public class CsvUtilTest {
 		students.add(student2);
 		students.add(student3);
 		writer.writeBeans(students);
+		writer.close();
 	}
 
 	@Test