参考:《第一行代码》
Java部分还不是很熟,渣渣在努力
在安卓的数据存储方式中有一招是文件存储,当然安卓内置有Context类的openFileOutput()方法将数据存储到指定文件中,有openFileInput()方法打开指定文件。openFileOuput()方法返回一个FileOutputStream对象,openFileInput()方法返回一个FileInputStream对象,拿到这对象以后就可以使用java流的方式将数据写入或读出文件了。
java流文件写入
openFileOutput()方法返回FileOutputStream对象,再拿到OutputStreamWriter(中间桥梁)对象,再拿到BufferedWriter(缓冲)对象,再调用write()方法写入,注意close(),
public void save(String inputText){
FileOutputStream out=null;
BufferedWriter writer=null;
try {
out=openFileOutput("data", MODE_PRIVATE);
writer=new BufferedWriter(new OutputStreamWriter(out));
writer.write(inputText);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
if(writer!=null){
try {
writer.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
java流的文件读出(与写入对应,为加深记忆,再写一遍)
首先,openFileInput()拿到FileInputStream对象,再通过这个对象拿到InputStreamReader对象,再通过InputStreamReader对象拿到BufferedReader对象,从而调用readline()方法进行读出,不要忘了close(),
public String load(){
FileInputStream inputStream=null;
BufferedReader reader=null;
StringBuilder contentBuilder=new StringBuilder();
try {
inputStream=openFileInput("data");
reader=new BufferedReader(new InputStreamReader(inputStream));
String line="";
while((line=reader.readLine())!=null){
contentBuilder.append(line);
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
if(reader!=null){
try {
reader.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return contentBuilder.toString();
}