我们java中的io流分为两大类,字节流和字符流。
可是在具体使用的时候怎么视情况进行使用?
怎么使用更加有效率?
有两个例子,帮忙看看解释一下,用哪种比较有效率以及适用情况。
下面是用字符流进行读写
写入:
FileOutputStream out = null;
BufferedWriter writer = null;
try {
out = openFileOutput("data", Context.MODE_PRIVATE);
writer = new BufferedWriter(new OutputStreamWriter(out));
writer.write(inputText);
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (writer != null) {
//关闭
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
读取
FileInputStream in = null;
BufferedReader reader = null;
StringBuilder content = new StringBuilder();
try {
in = openFileInput("data");
reader = new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = reader.readLine()) != null) {
content.append(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
//关闭
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
下面使用字节流读写
写入
public void WriteFiles(String content){
try {
FileOutputStream fos = openFileOutput("a.txt", MODE_WORLD_READABLE+MODE_WORLD_WRITEABLE);
fos.write(content.getBytes());
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
读取
public String readFiles(){
String content = null;
try {
FileInputStream fis= openFileInput("a.txt");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte [] buffer = new byte[1024];
int len = 0;
while ((len=fis.read(buffer))!=-1) {
baos.write(buffer, 0, len);
}
content = baos.toString();
fis.close();
baos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return content;
}
如果单纯数据传输的话用字节流,因为字符流还涉及编码的转换等操作会浪费时间。看下nio是否能提升你的速度?