在前面的 OSGL 工具库之编程艺术系列中我们讲述了

• 图像处理的艺术
• 图像处理的艺术之用户定义处理器
• 字串处理的艺术

本文中我们将介绍如何使用 OSGL IO 工具类来处理输入输出操作.

依旧是老规矩: 用代码来写博客

首先准备测试变量:

@Ignore
public static class Base extends TestBase {protected static String content;protected static C.List<String> lines;protected static int lineNumber;@Beforepublic void prepareContent() {lineNumber = 5 + N.randInt(10);lines = C.newList();for (int i = 0; i < lineNumber; ++i) {lines.add(S.random());}content = S.join(lines).by("\n").get();}
}

下面的测试代码可以看出如何使用 IO 库进行操作:

public static class FluentIOTest extends Base {@Testpublic void testReadStringIntoLines() {eq(lines, IO.read(content).toLines());}@Testpublic void testWriteStringIntoOutputStream() {ByteArrayOutputStream baos = new ByteArrayOutputStream();IO.write(content).to(baos);eq(content, new String(baos.toByteArray()));}@Testpublic void testWriteByteArrayIntoOutputStream() {byte[] ba = {1, 2, 3};ByteArrayOutputStream baos = new ByteArrayOutputStream();IO.write(ba).to(baos);eq(ba, baos.toByteArray());}@Testpublic void testWriteByteArrayIntoFile() throws IOException  {File file = File.createTempFile("osgl", ".tmp");byte[] ba = {1, 2, 3};IO.write(ba).to(file);byte[] ba0 = IO.read(file).toByteArray();eq(ba, ba0);}
}

其他 IO 工具演示:

Flushable f;
IO.flush(f);Closable c;
IO.close(c);InputStream is;
is = IO.inputStream(); // an empty inputstream
is = IO.inputStream("ABC"); // an input stream of string "ABC"
is = IO.inputStream(new byte[]{1, 2, 3});
is = IO.inputStream(new File("/etc/bash.bashrc"));
is = IO.inputStream(MyClass.getResource("/app.properties"));Reader r;
r = IO.reader(); // an empty reader
r = IO.reader("ABC");
r = IO.reader("ABC".getBytes()):
r = IO.reader(new File("/etc/bash.bashrc"));
r = IO.reader(MyClas.getResource("/app.properties"));File tmpDir = new File("/tmp");
File tmpFoo = IO.child(tmpDir, "foo.txt"); // /tmp/foo.txt
File tmpDir2 = IO.parent(tmpFoo);
List<File> files = IO.children(tmpDir);String s0 = IO.checksum(new File("/etc/bash.bashrc"));
String s1 = IO.checksum(IO.inputStream(new File("/etc/bash.bashrc"));BufferedInputStream is0 = IO.buffered(myOtherInputStream);
BufferedOutputStream os0 = IO.buffered(myOtherOutputStream);
BufferedReader r0 = IO.buffered(myOtherReader);
BufferedWriter w0 = IO.buffered(myOtherWriter);File tmpZip = IO.zip(f0, f1, ...);
File givenZipFile = ...
IO.zipInto(givenZipFile, f0, f1, ...);

特别提示, OSGL IO 库所有的操作都不会抛出 IOException 异常, 如果有 IO 异常, OSGL IO 库会抛出 UnexpectedIOException 运行时异常.