{"id":1178,"date":"2016-08-18T17:47:31","date_gmt":"2016-08-18T09:47:31","guid":{"rendered":"http:\/\/www.yeetrack.com\/?p=1178"},"modified":"2016-08-18T23:10:30","modified_gmt":"2016-08-18T15:10:30","slug":"%e8%b5%b0%e8%bf%91guava%e4%b8%83-%e6%96%87%e4%bb%b6%e6%93%8d%e4%bd%9c","status":"publish","type":"post","link":"https:\/\/www.yeetrack.com\/?p=1178","title":{"rendered":"\u8d70\u8fd1Guava(\u4e03): \u6587\u4ef6\u64cd\u4f5c"},"content":{"rendered":"
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\u6587\u4ef6\u64cd\u4f5c\uff1a<\/h1>\n
    \n
  • \u590d\u5236\u6587\u4ef6<\/span><\/li>\n<\/ul>\n
    File original  = new File(\"path\/to\/original\");\nFile copy = new File(\"path\/to\/copy\");\nFiles.copy(original, copy);<\/code><\/pre>\n
      \n
    • \u6587\u4ef6\u79fb\u52a8\/\u91cd\u547d\u540d<\/span><\/li>\n<\/ul>\n
      File original = new File(\"src\/main\/resources\/copy.txt\");\n\n\nFile newFile = new File(\"src\/main\/resources\/newFile.txt\");\ntry{\n   Files.move(original, newFile); \/\/\u79fb\u52a8\u6216\u91cd\u547d\u540d\u6587\u4ef6\uff0c\u7c7b\u4f3cUnix\u4e2d\u7684mv\n}catch (IOException e){\n   e.printStackTrace();\n}<\/code><\/pre>\n
        \n
      • \u5c06\u6587\u4ef6\u8bfb\u53d6\u4e3a\u5b57\u7b26\u4e32\u5217\u8868<\/span><\/li>\n<\/ul>\n
        List<String> readLines = Files.readLines(file, Charsets.UTF_8);<\/code><\/pre>\n
          \n
        • \u4e3a\u6587\u4ef6\u751f\u6210hash\u503c<\/span><\/li>\n<\/ul>\n
          File file = new File(\"src\/main\/resources\/sampleTextFileOne.txt\");\nHashCode hashCode = Files.hash(file, Hashing.md5());\nSystem.out.println(hashCode);<\/code><\/pre>\n
            \n
          • \u5199\u6216\u8ffd\u52a0\u6587\u4ef6<\/span><\/li>\n<\/ul>\n
            File file = new File(\"quote1.txt\");\nString hamletQuoteStart = \"To be, or not to be\";\nFiles.write(hamletQuoteStart,file, Charsets.UTF_8);\/\/\u5199\u6587\u4ef6\n         \nString hamletQuoteEnd = \",that is the question\";\nFiles.append(hamletQuoteEnd,file,Charsets.UTF_8); \/\/\u8ffd\u52a0\u6587\u4ef6\n         \nString overwrite = \"Overwriting the file\";\nFiles.write(overwrite, file, Charsets.UTF_8); \/\/\u91cd\u5199\u6587\u4ef6<\/code><\/pre>\n
            ByteSource\u7c7b<\/h2>\n
              \n
            • ByteSource<\/span>\u4ee3\u8868\u4e00\u4e2a\u53ef\u8bfb\u7684<\/span>\u5b57\u8282\u6e90<\/span><\/li>\n<\/ul>\n
                \n
              • \u4ece\u6587\u4ef6\u521b\u5efaByteSource<\/span><\/li>\n<\/ul>\n
                File f1 = new File(\"quote1.txt\");\nByteSource byteSource = Files.asByteSource(f1);\nbyte[] readBytes = byteSource.read();\nSystem.out.println(readBytes);<\/code><\/pre>\n
                ByteSink\u7c7b<\/h2>\n
                  \n
                • ByteSink<\/span>\u4ee3\u8868\u4e00\u4e2a\u53ef\u5199\u7684<\/span>\u5b57\u8282\u6e90<\/span><\/li>\n
                • \u521b\u5efaByteSink<\/span><\/li>\n<\/ul>\n
                  File dest = new File(\"destfile.txt\");\nByteSink byteSink = Files.asByteSink(dest);\nFile file = new File(\"srcfile.txt\");\nbyteSink.write(Files.toByteArray(file));<\/code><\/pre>\n
                    \n
                  • \u5c06ByteSource\u590d\u5236\u5230ByteSink<\/span><\/li>\n<\/ul>\n
                    File dest = new File(\"destfile.txt\");\nFile source = new File(\"srcfile.txt\");\nByteSource byteSource = Files.asByteSource(source);\nByteSink byteSink = Files.asByteSink(dest);\nbyteSource.copyTo(byteSink);<\/code><\/pre>\n
                    ByteStreams\u548cCharStreams<\/h2>\n
                      \n
                    • \u9650\u5236\u8f93\u5165\u6d41\u5927\u5c0f<\/span><\/li>\n<\/ul>\n
                      ByteStreams.limit(inputStream, 10)<\/code><\/pre>\n
                        \n
                      • \u5408\u5e76CharStreams<\/span><\/li>\n<\/ul>\n
                        @Test\npublic void joinCharStreamsTest() throws Exception {\n\tFile f1 = new File(\"file1.txt\");\n\tFile f2 = new File(\"file2.txt\");\n\tFile f3 = new File(\"file3.txt\");\n\tFile joinedOutput = new File(\"file123.txt\");\n\n\tList<InputSupplier<InputStreamReader>> inputSuppliers = getInputSuppliers(f1, f2, f3);\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0InputSupplier<Reader> joinedSupplier = CharStreams.join(inputSuppliers);\n\tOutputSupplier<OutputStreamWriter> outputSupplier = Files.newWriterSupplier(joinedOutput, Charsets.UTF_8);\n\tCharStreams.copy(joinedSupplier, outputSupplier);\n\tString joinedOutputString = joinFiles(joinedOutput);\n\tSystem.out.println(joinedOutputString);\n}\n\/\/\u5c06\u591a\u4e2a\u6587\u4ef6\u5408\u5e76\u4e3a\u5b57\u7b26\u4e32\nprivate String joinFiles(File... files) throws IOException {\n\tStringBuilder builder = new StringBuilder();\n\tfor (File file : files) {\n\t\tbuilder.append(Files.toString(file, Charsets.UTF_8));\n\t}\n\treturn builder.toString();\n}\n\/\/\u5c06\u591a\u4e2a\u6587\u4ef6\u8f6c\u6362\u4e3aInputSuppler<InputStreamReader>\u7c7b\u578b\u7684\u5217\u8868\nprivate List<InputSupplier<InputStreamReader>> getInputSuppliers(File... files) {\n\tList<InputSupplier<InputStreamReader>> list = Lists.newArrayList();\n\tfor (File file : files) {\n\t\tlist.add(Files.newReaderSupplier(file, Charsets.UTF_8));\n\t}\n\treturn list;\n}<\/code><\/pre>\n
                        Closer\u7c7b<\/h2>\n
                          \n
                        • Cl<\/span>oser<\/span>\u53ef\u4ee5\u4fdd\u8bc1\u6ce8\u518c\u7684Closable<\/span>\u5bf9\u8c61\uff0c\u5728Closer\u5173\u95ed\u65f6\uff0c\u6ce8\u518c\u7684Closable\u5bf9\u8c61\u4e5f\u4f1a\u88ab\u5173\u95ed\u3002<\/span><\/li>\n<\/ul>\n
                          Closer closer = Closer.create();\ntry {\n\tFile destination = new File(\"destfile.txt\");\n\tBufferedReader reader = new BufferedReader(new FileReader(\"srcfile.txt\"));\n\tBufferedWriter writer = new BufferedWriter(new FileWriter(destination));\n\tcloser.register(reader);\n\tcloser.register(writer);\n\tString line;\n\twhile ((line = reader.readLine()) != null) {\n\t\twriter.write(line);\n\t}\n} catch (Throwable t) {\n\tthrow closer.rethrow(t);\n} finally {\n\tcloser.close();\n}<\/code><\/pre>\n
                          BaseEncoding\u7c7b<\/h2>\n
                            \n
                          • BaseEncoding\u9488\u5bf9\u5b57\u8282\u7801\u7684\u7f16\u7801\u5de5\u4f5c\u3002<\/span><\/li>\n<\/ul>\n
                              \n
                            • \u4e00\u4e9b\u7528\u4f8b<\/span><\/li>\n<\/ul>\n
                              @Test\npublic void encodeDecodeTest() throws Exception {\n\tFile file = new File(\"srcfile.txt\");\n\tbyte[] bytes = Files.toByteArray(file);\n\tBaseEncoding baseEncoding = BaseEncoding.base64();\n\tString encoded = baseEncoding.encode(bytes); \/\/ \u5c06\u5b57\u8282\u4ee5Base64\u7f16\u7801\n}\n\n@Test\npublic void encodeByteSinkTest() throws Exception {\n\tFile srcFile = new File(\"srcfile.txt\");\n\tFile encodedFile = new File(\"encodedfile.txt\");\n\tCharSink charSink = Files.asCharSink(encodedFile, Charsets.UTF_8);\n\tBaseEncoding baseEncoding = BaseEncoding.base64();\n\tByteSink byteSink = baseEncoding.encodingSink(charSink); \/\/\u5c06charSink\u8f6c\u4e3aByteSink\n\tByteSource byteSource = Files.asByteSource(srcFile);\n\tbyteSource.copyTo(byteSink); \/\/copy ByteSource to ByteSink\n\tString encodedBytes = baseEncoding.encode(byteSource.read());\n}<\/code><\/pre>\n
                              \u4ee5\u4e0a\u5c31\u662fGuava\u7684\u6587\u4ef6\u5904\u7406\u3002<\/p>\n
                              \u6765\u6e90:http:\/\/my.oschina.net\/indestiny\/blog\/219802<\/p>\n
                              \n
                              \u8d70\u8fd1Guava(\u4e00): \u57fa\u672c\u5de5\u5177<\/a><\/p><\/blockquote>\n