Android中读取中文字符的文件与文件读取相关介绍

一、如何显示assets/license.txt（中文）的内容？
(1)方法1：InputStream.available()得到字节数，然后一次读取完。

private String readUserAgreementFromAsset(String assetName) {
String content ="";
try {
InputStream is= getAssets().open(assetName);
if (is != null){
DataInputStream dIs = newDataInputStream(is);
intlength = dIs.available();
byte[] buffer = new byte[length];
dIs.read(buffer);
content= EncodingUtils.getString(buffer, "UTF-8");
is.close();
}
} catch (IOException e) {
e.printStackTrace();
}
return content;
}

(2)方法2：用BufferedReader.readLine()行读取再加换行符，最后用StringBuilder.append()连接成字符串。
A.以下是先行读取再转码UTF8：

private String readUserAgreementFromAsset(String assetName) {
StringBuilder sb = newStringBuilder("");
String content ="";
try {
InputStream is= getAssets().open(assetName);
if (is != null){
BufferedReader d = newBufferedReader(new InputStreamReader(is));
while (d.ready()) {
sb.append(d.readLine() +"\n");
}
content =EncodingUtils.getString(sb.toString().getBytes(), "UTF-8");
is.close();
}
} catch (IOException e) {
e.printStackTrace();
}
return content;
}

B.以下是InputStreamReader先指定以UTF8读取文件，再进行读取读取操作：

private String readUserAgreementFromAsset(String assetName) {
StringBuilder sb = newStringBuilder("");
String content ="";
try {
InputStream is= getAssets().open(assetName);
if (is != null){
BufferedReaderd = new BufferedReader(new InputStreamReader(is, "UTF-8"));
while(d.ready()) {
sb.append(d.readLine() +"\n");
}
content= sb.toString();
is.close();
}
} catch (IOException e) {
e.printStackTrace();
}
return content;
}

另外，UTF8转码也可以用new String(buffer, “utf-8”)。
(3)替代方法3：将license.txt内容作为string.xml的string，如：
<stringname="license_content">用户协议
\n \n一、服务条款的确认和接纳
\n…
</string>
需要注意的是：string里需要加\n作为换行符，原来txt里的换行符在取得string后无效。
不可取方法4：每次读取4096字节，以UTF8转码，最后连接字符串。因为汉字可能被截断，导致4096的倍数附近的中文可能出现乱码。

private String readUserAgreementFromAsset(String assetName) {
StringBuilder sb = newStringBuilder("");
String content ="";
try {
InputStream is= getAssets().open(assetName);
if (is != null){
DataInputStream dIs = new DataInputStream(is);
byte[] buffer = new byte[1024*4];
int length = 0;
while ((length = dIs.read(buffer)) >0) {
content =EncodingUtils.getString(buffer, 0, length, "UTF-8");
sb.append(content);
}
is.close();
}
} catch (IOException e) {
e.printStackTrace();
}
return sb.toString();
}

https://www.jb51.net/kf/201207/140312.html
http://blog.sina.com.cn/s/blog_933d50ba0100wq1h.html
二、Android中读写文件
(1) 从resource中的raw文件夹中获取文件并读取数据（资源文件只能读不能写，\res\raw\test.txt）

String res = "";
try{
InputStream in = getResources().openRawResource(R.raw.test);
int length = in.available();
byte [] buffer = newbyte[length];
in.read(buffer);
res = EncodingUtils.getString(buffer,"UTF-8");//选择合适的编码，如果不调整会乱码
in.close();
}catch(Exception e){
e.printStackTrace();
}

(2) 从asset中获取文件并读取数据（资源文件只能读不能写，\assets\test.txt）
与raw文件夹类似，只是：
InputStream is = getAssets().open(“test.txt”);
(3) 私有文件夹下的文件存取（/data/data/包名/files/test.txt）
使用openFileOutput写文件：

public void writeFileData(String fileName,String message){
try{
FileOutputStream fout =openFileOutput(fileName,MODE_PRIVATE);
byte [] bytes =message.getBytes();
fout.write(bytes);
fout.close();
}
catch(Exception e){
e.printStackTrace();
}
}

使用openFileInput读文件：

public String readFileData(String fileName){
String str = “”;
try{
FileInputStream fin =openFileInput(fileName);
int length = in.available();
byte [] bytes = newbyte[length];
fin.read(bytes);
str = EncodingUtils.getString(bytes,"UTF-8");
fin.close();
}
catch(Exception e){
e.printStackTrace();
}
return str;
}

(4) sdcard目录下的文件存取（/mnt/sdcard/）
使用FileOutputStream写文件：

public void writeFile2Sdcard(String fileName,String message){
try{
FileOutputStream fout = new FileOutputStream(fileName);
byte [] bytes =message.getBytes();
fout.write(bytes);
fout.close();
}
catch(Exception e){
e.printStackTrace();
}
}

使用FileInputStream读文件：

public String readFileFromSdcard(String fileName){
String res="";
try{
FileInputStream fin = newFileInputStream(fileName);
int length =fin.available();
byte [] buffer = newbyte[length];
fin.read(buffer);
res =EncodingUtils.getString(buffer, "UTF-8");
fin.close();
}
catch(Exception e){
e.printStackTrace();
}
return res;
}

http://dev.10086.cn/cmdn/wiki/index.php?doc-view-6017.html
http://blog.sina.com.cn/s/blog_4d25c9870100qpax.html