xml
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/et_5"
android:hint="要存储的的内容"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/et_6"
android:hint="从文件中读取的内容"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="保存到带包名的目录"
android:layout_weight="1"
android:onClick="onclick7"/>
<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="从带包名的目录中获取"
android:layout_weight="1"
android:onClick="onclick8"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="保存到自定义的目录"
android:layout_weight="1"
android:onClick="onclick9"/>
<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="从自定义的目录中获取"
android:layout_weight="1"
android:onClick="onclick10"/>
</LinearLayout>
java
需要权限
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
//向外部空间存储文件 保存到带包名的目录
public void onclick7(View view)
{
//
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
//1.获取要存储的内容
String content = et_5.getText().toString(); //2.获取外部存储带包名的目录 ——只到根目录
// String sdpath = Environment.getExternalStorageDirectory().getAbsolutePath();
//Toast.makeText(Activitydata.this, "sdpath= "+sdpath, Toast.LENGTH_LONG).show(); //参数 代表不同文件类型的子目录 如果没有就传null 获取到根目录下的带包名的目录
String sdpath = getExternalFilesDir(null).getAbsolutePath();
Toast.makeText(Activitydata.this, "sdpath= "+sdpath, Toast.LENGTH_LONG).show(); //3.构造输出流
sdpath += "/" +FILENAME; try {
FileOutputStream fos = new FileOutputStream(sdpath,true); //传统方式 字节数组方式
fos.write(content.getBytes("utf-8")); fos.close(); Toast.makeText(Activitydata.this, "保存成功", Toast.LENGTH_SHORT).show(); } catch (Exception e) {
e.printStackTrace();
Toast.makeText(Activitydata.this, "保存失败", Toast.LENGTH_SHORT).show();
}
}
else
{
Toast.makeText(Activitydata.this, "sd卡没有挂载", Toast.LENGTH_SHORT).show();
} } //从外部存储空间中读取带包名文件
//判断是否挂载
public void onclick8(View view)
{
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
//1.获取要存储的内容
//String content = et_5.getText().toString(); //2.获取外部存储带包名的目录 ——只到根目录
// String sdpath = Environment.getExternalStorageDirectory().getAbsolutePath();
//Toast.makeText(Activitydata.this, "sdpath= "+sdpath, Toast.LENGTH_LONG).show(); //参数 代表不同文件类型的子目录 如果没有就传null 获取到根目录下的带包名的目录
String sdpath = getExternalFilesDir(null).getAbsolutePath();
// Toast.makeText(Activitydata.this, "sdpath= "+sdpath, Toast.LENGTH_LONG).show(); //3.构造输入流
sdpath += "/" +FILENAME; try {
FileInputStream fis = new FileInputStream(sdpath); byte[] b = new byte[1024]; int i = 0; StringBuilder sbr = new StringBuilder(); while ((i = fis.read(b))>0)
{
sbr.append(new String(b,0,i));
et_6.setText(sbr);
}
fis.close(); Toast.makeText(Activitydata.this, "获取成功", Toast.LENGTH_SHORT).show(); } catch (Exception e) {
e.printStackTrace();
Toast.makeText(Activitydata.this, "获取失败", Toast.LENGTH_SHORT).show();
}
}
else
{
Toast.makeText(Activitydata.this, "sd卡没有挂载", Toast.LENGTH_SHORT).show();
}
} //保存文件到自定义目录
public void onclick9(View view)
{ if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
//1.获取要存储的内容
String content = et_5.getText().toString(); //2.获取外部存储的根目录
String sdpath = Environment.getExternalStorageDirectory().getAbsolutePath(); //在sd卡的根目录下创建子目录
sdpath += "/hanqi"; //实例化File，指向一个目录
File file = new File(sdpath); //如果不存在创建一个
if (!file.exists()) {
//创建目录
file.mkdirs();
}
Toast.makeText(Activitydata.this, "path= " + sdpath, Toast.LENGTH_SHORT).show(); //3.创建输出流
sdpath += "/" + FILENAME; try {
FileOutputStream fos = new FileOutputStream(sdpath, true); //传统方式 字节数组方式
fos.write(content.getBytes("utf-8")); fos.close(); Toast.makeText(Activitydata.this, "保存成功", Toast.LENGTH_SHORT).show(); } catch (Exception e) {
e.printStackTrace();
Toast.makeText(Activitydata.this, "保存失败", Toast.LENGTH_SHORT).show();
}
} else
{
Toast.makeText(Activitydata.this, "sd卡没有挂载", Toast.LENGTH_SHORT).show();
} } public void onclick10(View view){ if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
//1.获取要存储的内容
//String content = et_5.getText().toString(); //2.获取外部存储带包名的目录 ——只到根目录
String sdpath = Environment.getExternalStorageDirectory().getAbsolutePath();
//Toast.makeText(Activitydata.this, "sdpath= "+sdpath, Toast.LENGTH_LONG).show(); //参数 代表不同文件类型的子目录 如果没有就传null 获取到根目录下的带包名的目录
//String sdpath = getExternalFilesDir(null).getAbsolutePath();
// Toast.makeText(Activitydata.this, "sdpath= "+sdpath, Toast.LENGTH_LONG).show(); //3.构造输入流
sdpath += "/hanqi/" +FILENAME; Toast.makeText(Activitydata.this, ""+sdpath, Toast.LENGTH_SHORT).show(); try {
FileInputStream fis = new FileInputStream(sdpath); byte[] b = new byte[1024]; int i = 0; StringBuilder sbr = new StringBuilder(); while ((i = fis.read(b))>0)
{
sbr.append(new String(b,0,i));
et_6.setText(sbr);
}
fis.close(); Toast.makeText(Activitydata.this, "获取成功", Toast.LENGTH_SHORT).show(); } catch (Exception e) {
e.printStackTrace();
Toast.makeText(Activitydata.this, "获取失败", Toast.LENGTH_SHORT).show();
}
}
else
{
Toast.makeText(Activitydata.this, "sd卡没有挂载", Toast.LENGTH_SHORT).show();
} }
