add methods

CHANGELOG.md

@@ -23,6 +23,7 @@
 * 【core   】     LambdaUtil添加getFieldName（issue#I4750U@Gitee）
 * 【cron   】     Scheduler增加setThreadExecutor（issue#I47A6N@Gitee）
 * 【core   】     CharsetDetector增加detect重载，支持自定义缓存大小（issue#I478E5@Gitee）
+* 【core   】     增加PartitionIter（pr#402@Gitee）
 
 ### 🐞Bug修复
 * 【core   】     修复MapUtil.sort比较器不一致返回原map的问题（issue#I46AQJ@Gitee）

hutool-core/src/main/java/cn/hutool/core/collection/Partition.java

@@ -15,8 +15,8 @@ import java.util.List;
  */
 public class Partition<T> extends AbstractList<List<T>> {
 
-	final List<T> list;
+	protected final List<T> list;
-	final int size;
+	protected final int size;
 
 	/**
 	 * 列表分区

hutool-core/src/main/java/cn/hutool/core/collection/PartitionIter.java

@@ -0,0 +1,64 @@
+package cn.hutool.core.collection;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * 分批迭代工具，可以分批处理数据
+ * <ol>
+ *     <li>比如调用其他客户的接口，传入的入参有限，需要分批</li>
+ *     <li>比如mysql/oracle用in语句查询，超过1000可以分批</li>
+ *     <li>比如数据库取出游标，可以把游标里的数据一批一批处理</li>
+ * </ol>
+ *
+ * @param <T> 字段类型
+ * @author qiqi.chen
+ * @since 5.7.10
+ */
+public class PartitionIter<T> implements Iterator<List<T>>, Iterable<List<T>>, Serializable {
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * 被分批的迭代器
+	 */
+	protected final Iterator<T> iterator;
+	/**
+	 * 实际每批大小
+	 */
+	protected final int partitionSize;
+
+	/**
+	 * 创建分组对象
+	 *
+	 * @param iterator      迭代器
+	 * @param partitionSize 每批大小，最后一批不满一批算一批
+	 */
+	public PartitionIter(Iterator<T> iterator, int partitionSize) {
+		this.iterator = iterator;
+		this.partitionSize = partitionSize;
+	}
+
+	@Override
+	public Iterator<List<T>> iterator() {
+		return this;
+	}
+
+	@Override
+	public boolean hasNext() {
+		return this.iterator.hasNext();
+	}
+
+	@Override
+	public List<T> next() {
+		final List<T> list = new ArrayList<>(this.partitionSize);
+		for (int i = 0; i < this.partitionSize; i++) {
+			if (false == iterator.hasNext()) {
+				break;
+			}
+			list.add(iterator.next());
+		}
+		return list;
+	}
+}

hutool-core/src/main/java/cn/hutool/core/io/FileUtil.java

@@ -685,8 +685,8 @@ public class FileUtil extends PathUtil {
 	 * 某个文件删除失败会终止删除操作
 	 *
 	 * <p>
-	 *     从5.7.6开始，删除文件使用{@link Files#delete(Path)}代替 {@link File#delete()}<br>
+	 * 从5.7.6开始，删除文件使用{@link Files#delete(Path)}代替 {@link File#delete()}<br>
-	 *     因为前者遇到文件被占用等原因时，抛出异常，而非返回false，异常会指明具体的失败原因。
+	 * 因为前者遇到文件被占用等原因时，抛出异常，而非返回false，异常会指明具体的失败原因。
 	 * </p>
 	 *
 	 * @param file 文件对象
@@ -712,7 +712,7 @@ public class FileUtil extends PathUtil {
 		final Path path = file.toPath();
 		try {
 			delFile(path);
-		} catch (DirectoryNotEmptyException e){
+		} catch (DirectoryNotEmptyException e) {
 			// 遍历清空目录没有成功，此时补充删除一次（可能存在部分软链）
 			del(path);
 		} catch (IOException e) {
@@ -754,7 +754,7 @@ public class FileUtil extends PathUtil {
 		final File[] files = directory.listFiles();
 		if (null != files) {
 			for (File childFile : files) {
-				if(false == del(childFile)){
+				if (false == del(childFile)) {
 					// 删除一个出错则本次删除任务失败
 					return false;
 				}
@@ -1401,7 +1401,7 @@ public class FileUtil extends PathUtil {
 	 */
 	@Deprecated
 	public static boolean isModifed(File file, long lastModifyTime) {
-		return isModified(file,lastModifyTime);
+		return isModified(file, lastModifyTime);
 	}
 
 
@@ -1815,9 +1815,11 @@ public class FileUtil extends PathUtil {
 	 * @param charsetName 字符集
 	 * @return BufferedReader对象
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #getReader(File, Charset)}
 	 */
+	@Deprecated
 	public static BufferedReader getReader(File file, String charsetName) throws IORuntimeException {
-		return IoUtil.getReader(getInputStream(file), charsetName);
+		return IoUtil.getReader(getInputStream(file), CharsetUtil.charset(charsetName));
 	}
 
 	/**
@@ -1839,9 +1841,11 @@ public class FileUtil extends PathUtil {
 	 * @param charsetName 字符集
 	 * @return BufferedReader对象
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #getReader(String, Charset)}
 	 */
+	@Deprecated
 	public static BufferedReader getReader(String path, String charsetName) throws IORuntimeException {
-		return getReader(file(path), charsetName);
+		return getReader(path, CharsetUtil.charset(charsetName));
 	}
 
 	/**
@@ -1912,7 +1916,9 @@ public class FileUtil extends PathUtil {
 	 * @param charsetName 字符集
 	 * @return 内容
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #readString(File, Charset)}
 	 */
+	@Deprecated
 	public static String readString(File file, String charsetName) throws IORuntimeException {
 		return readString(file, CharsetUtil.charset(charsetName));
 	}
@@ -1936,9 +1942,11 @@ public class FileUtil extends PathUtil {
 	 * @param charsetName 字符集
 	 * @return 内容
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #readString(String, Charset)}
 	 */
+	@Deprecated
 	public static String readString(String path, String charsetName) throws IORuntimeException {
-		return readString(file(path), charsetName);
+		return readString(path, CharsetUtil.charset(charsetName));
 	}
 
 	/**
@@ -1953,6 +1961,20 @@ public class FileUtil extends PathUtil {
 		return readString(file(path), charset);
 	}
 
+	/**
+	 * 读取文件内容
+	 *
+	 * @param url         文件URL
+	 * @param charsetName 字符集
+	 * @return 内容
+	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #readString(URL, Charset)}
+	 */
+	@Deprecated
+	public static String readString(URL url, String charsetName) throws IORuntimeException {
+		return readString(url, CharsetUtil.charset(charsetName));
+	}
+
 	/**
 	 * 读取文件内容
 	 *
@@ -1960,8 +1982,9 @@ public class FileUtil extends PathUtil {
 	 * @param charset 字符集
 	 * @return 内容
 	 * @throws IORuntimeException IO异常
+	 * @since 5.7.10
 	 */
-	public static String readString(URL url, String charset) throws IORuntimeException {
+	public static String readString(URL url, Charset charset) throws IORuntimeException {
 		if (url == null) {
 			throw new NullPointerException("Empty url provided!");
 		}
@@ -2083,7 +2106,9 @@ public class FileUtil extends PathUtil {
 	 * @param collection  集合
 	 * @return 文件中的每行内容的集合
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #readLines(URL, Charset, Collection)}
 	 */
+	@Deprecated
 	public static <T extends Collection<String>> T readLines(URL url, String charsetName, T collection) throws IORuntimeException {
 		return readLines(url, CharsetUtil.charset(charsetName), collection);
 	}
@@ -2125,13 +2150,15 @@ public class FileUtil extends PathUtil {
 	/**
 	 * 从文件中读取每一行数据
 	 *
-	 * @param url     文件的URL
+	 * @param url         文件的URL
-	 * @param charset 字符集
+	 * @param charsetName 字符集
 	 * @return 文件中的每行内容的集合List
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #readLines(URL, Charset)}
 	 */
-	public static List<String> readLines(URL url, String charset) throws IORuntimeException {
+	@Deprecated
-		return readLines(url, charset, new ArrayList<>());
+	public static List<String> readLines(URL url, String charsetName) throws IORuntimeException {
+		return readLines(url, CharsetUtil.charset(charsetName));
 	}
 
 	/**
@@ -2412,9 +2439,11 @@ public class FileUtil extends PathUtil {
 	 * @param isAppend    是否追加
 	 * @return BufferedReader对象
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #getWriter(String, Charset, boolean)}
 	 */
+	@Deprecated
 	public static BufferedWriter getWriter(String path, String charsetName, boolean isAppend) throws IORuntimeException {
-		return getWriter(touch(path), Charset.forName(charsetName), isAppend);
+		return getWriter(path, Charset.forName(charsetName), isAppend);
 	}
 
 	/**
@@ -2438,7 +2467,9 @@ public class FileUtil extends PathUtil {
 	 * @param isAppend    是否追加
 	 * @return BufferedReader对象
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #getWriter(File, Charset, boolean)}
 	 */
+	@Deprecated
 	public static BufferedWriter getWriter(File file, String charsetName, boolean isAppend) throws IORuntimeException {
 		return getWriter(file, Charset.forName(charsetName), isAppend);
 	}

hutool-core/src/main/java/cn/hutool/core/io/IoUtil.java

@@ -206,7 +206,9 @@ public class IoUtil extends NioUtil {
 	 * @param in          输入流
 	 * @param charsetName 字符集名称
 	 * @return BufferedReader对象
+	 * @deprecated 请使用 {@link #getReader(InputStream, Charset)}
 	 */
+	@Deprecated
 	public static BufferedReader getReader(InputStream in, String charsetName) {
 		return getReader(in, Charset.forName(charsetName));
 	}
@@ -290,7 +292,9 @@ public class IoUtil extends NioUtil {
 	 * @param out         输入流
 	 * @param charsetName 字符集
 	 * @return OutputStreamWriter对象
+	 * @deprecated 请使用 {@link #getWriter(OutputStream, Charset)}
 	 */
+	@Deprecated
 	public static OutputStreamWriter getWriter(OutputStream out, String charsetName) {
 		return getWriter(out, Charset.forName(charsetName));
 	}
@@ -336,7 +340,9 @@ public class IoUtil extends NioUtil {
 	 * @param charsetName 字符集
 	 * @return 内容
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #read(InputStream, Charset)}
 	 */
+	@Deprecated
 	public static String read(InputStream in, String charsetName) throws IORuntimeException {
 		final FastByteArrayOutputStream out = read(in);
 		return StrUtil.isBlank(charsetName) ? out.toString() : out.toString(charsetName);
@@ -637,7 +643,9 @@ public class IoUtil extends NioUtil {
 	 * @param collection  返回集合
 	 * @return 内容
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #readLines(InputStream, Charset, Collection)}
 	 */
+	@Deprecated
 	public static <T extends Collection<String>> T readLines(InputStream in, String charsetName, T collection) throws IORuntimeException {
 		return readLines(in, CharsetUtil.charset(charsetName), collection);
 	}
@@ -697,7 +705,8 @@ public class IoUtil extends NioUtil {
 
 	/**
 	 * 按行读取数据，针对每行的数据做处理<br>
-	 * {@link Reader}自带编码定义，因此读取数据的编码跟随其编码。
+	 * {@link Reader}自带编码定义，因此读取数据的编码跟随其编码。<br>
+	 * 此方法不会关闭流，除非抛出异常
 	 *
 	 * @param reader      {@link Reader}
 	 * @param lineHandler 行处理接口，实现handle方法用于编辑一行的数据后入到指定地方
@@ -707,15 +716,8 @@ public class IoUtil extends NioUtil {
 		Assert.notNull(reader);
 		Assert.notNull(lineHandler);
 
-		// 从返回的内容中读取所需内容
+		for (String line : lineIter(reader)) {
-		final BufferedReader bReader = getReader(reader);
+			lineHandler.handle(line);
-		String line;
-		try {
-			while ((line = bReader.readLine()) != null) {
-				lineHandler.handle(line);
-			}
-		} catch (IOException e) {
-			throw new IORuntimeException(e);
 		}
 	}
 
@@ -727,7 +729,9 @@ public class IoUtil extends NioUtil {
 	 * @param content     内容
 	 * @param charsetName 编码
 	 * @return 字节流
+	 * @deprecated 请使用 {@link #toStream(String, Charset)}
 	 */
+	@Deprecated
 	public static ByteArrayInputStream toStream(String content, String charsetName) {
 		return toStream(content, CharsetUtil.charset(charsetName));
 	}
@@ -1008,7 +1012,9 @@ public class IoUtil extends NioUtil {
 	 * @param isCloseOut  写入完毕是否关闭输出流
 	 * @param contents    写入的内容，调用toString()方法，不包括不会自动换行
 	 * @throws IORuntimeException IO异常
+	 * @deprecated 请使用 {@link #write(OutputStream, Charset, boolean, Object...)}
 	 */
+	@Deprecated
 	public static void write(OutputStream out, String charsetName, boolean isCloseOut, Object... contents) throws IORuntimeException {
 		write(out, CharsetUtil.charset(charsetName), isCloseOut, contents);
 	}

hutool-core/src/test/java/cn/hutool/core/collection/CollStreamUtilTest.java

@@ -81,6 +81,7 @@ public class CollStreamUtilTest {
 		Assert.assertEquals(map, compare);
 	}
 
+	@Test
 	public void testGroupBy2Key() {
 		Map<Long, Map<Long, List<Student>>> map = CollStreamUtil.groupBy2Key(null, Student::getTermId, Student::getClassId);
 		Assert.assertEquals(map, Collections.EMPTY_MAP);
@@ -229,4 +230,4 @@ public class CollStreamUtilTest {
 		private long studentId;//班级id
 		private String name;//学生名称
 	}
-}
+}

hutool-core/src/test/java/cn/hutool/core/collection/PartitionIterTest.java

@@ -0,0 +1,31 @@
+package cn.hutool.core.collection;
+
+import cn.hutool.core.io.resource.ResourceUtil;
+import cn.hutool.core.util.NumberUtil;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.List;
+
+public class PartitionIterTest {
+
+	@Test
+	public void iterTest() {
+		final LineIter lineIter = new LineIter(ResourceUtil.getUtf8Reader("test_lines.csv"));
+		final PartitionIter<String> iter = new PartitionIter<>(lineIter.iterator(), 3);
+		for (List<String> lines : iter) {
+			Assert.assertTrue(lines.size() > 0);
+		}
+	}
+
+	@Test
+	public void iterMaxTest() {
+		final List<Integer> list = ListUtil.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 0, 12, 45, 12);
+		final PartitionIter<Integer> iter = new PartitionIter<>(list.iterator(), 3);
+		int max = 0;
+		for (List<Integer> lines : iter) {
+			max = NumberUtil.max(max, NumberUtil.max(lines.toArray(new Integer[0])));
+		}
+		Assert.assertEquals(45, max);
+	}
+}

hutool-core/src/test/java/cn/hutool/core/io/IoUtilTest.java

@@ -4,6 +4,9 @@ import cn.hutool.core.io.resource.ResourceUtil;
 import org.junit.Assert;
 import org.junit.Test;
 
+import java.io.BufferedReader;
+import java.io.IOException;
+
 public class IoUtilTest {
 
 	@Test
@@ -11,4 +14,13 @@ public class IoUtilTest {
 		final byte[] bytes = IoUtil.readBytes(ResourceUtil.getStream("hutool.jpg"));
 		Assert.assertEquals(22807, bytes.length);
 	}
+
+	@Test
+	public void readLinesTest(){
+		try(BufferedReader reader = ResourceUtil.getUtf8Reader("test_lines.csv");){
+			IoUtil.readLines(reader, (LineHandler) Assert::assertNotNull);
+		} catch (IOException e) {
+			throw new IORuntimeException(e);
+		}
+	}
 }