目标是要存下传来的 GZIP 文件流，当然得解压好。iOS 做这件事是自觉自愿，Android 不做。于是我找啊找。如果 Native.js 也不行，那该去写原生插件了吧。结果确实不行，因为没法用上 buffer，一张图片几分钟才出来。讨论群里答疑说 Native.js 不是这么用的。呃，好吧。

最后我也没写插件，一时半会写不出。

handleAndroid(file, inFilePath, targetDir, fileName) {
                // #ifdef APP-PLUS
                var absInPath = plus.io.convertLocalFileSystemURL( inFilePath )
                var absOutPath = plus.io.convertLocalFileSystemURL( targetDir )
                console.log("in 路径：", absInPath)
                console.log("out 路径：", absOutPath) 
                var File = plus.android.importClass("java.io.File")
                var FileInputStream = plus.android.importClass("java.io.FileInputStream");
                var FileOutputStream = plus.android.importClass("java.io.FileOutputStream");
                var BufferedInputStream = plus.android.importClass("java.io.BufferedInputStream");
                var BufferedOutputStream = plus.android.importClass("java.io.BufferedOutputStream");
                var GZIPInputStream = plus.android.importClass("java.util.zip.GZIPInputStream");
                
                var inFile = new File(absInPath)
                console.log("inFile: ", inFile.canRead(), inFile.canWrite(), inFile.isFile(), inFile.length(), inFile.getAbsolutePath())
                
                if(inFile.exists()) {
                    var ins = new BufferedInputStream( new GZIPInputStream(new FileInputStream(absInPath)) )
                    
                    var directory = new File(absOutPath);
                    if(!directory.exists()) {
                        directory.mkdirs(); //创建目录
                    }
         
                    var outFile = new File(absOutPath + fileName);
         
                    if(!outFile.exists()) {
                        outFile.createNewFile(); //创建文件
                    }
                    
                    var os = new BufferedOutputStream( new FileOutputStream(absOutPath + fileName) )
                    
                    console.log("outFile: ", outFile.canRead(), outFile.canWrite(), outFile.isFile(), outFile.length(), outFile.getAbsolutePath())
                    
                    // var buf = new ArrayBuffer(1024)
                    // console.log("===", ins.read(buf))
                    var n
                    let count = 0
                    while ((n = ins.read()) != -1) { // 单字节
                        os.write(n);
                        
                        if(count%2000 == 0) {
                            console.log("count: ", count)
                            uni.showToast({
                                icon: 'loading',
                                title: String(count)
                            })
                        }
                        count++
                    }
                    
                    console.log("outFile: ", outFile.canRead(), outFile.canWrite(), outFile.isFile(), outFile.length(), outFile.getAbsolutePath())
                    ins.close()
                    os.close()                  
                    
                } else {
                    console.log("文件不存在")
                }
                // #endif
                
            },