Android json的使用

public class JSONActivity extends Activity
{
private String jsonFile = "/sdcard/test.json";

@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_json);
}

private static class Product
{
public String id;
public String name;

public Product(String id, String name)
{
this.id = id;
this.name = name;
}
}

public void writeProduct(JsonWriter writer, Product product)
throws IOException
{
writer.beginObject();
writer.name("id").value(product.id);
writer.name("name").value(product.name);
writer.endObject();
}

public void writeProductArray(JsonWriter writer, List<Product> products)
throws IOException
{
writer.beginArray();
for (Product product : products)
{
writeProduct(writer, product);
}
writer.endArray();
}

public void writeJsonStream(OutputStream out, List<Product> products)
throws IOException
{
JsonWriter writer = new JsonWriter(new OutputStreamWriter(out, "UTF-8"));
writer.setIndent("  ");
writeProductArray(writer, products);
writer.close();
}

public void onClick_WriteJSON(View view)
{
try
{
FileOutputStream fos = new FileOutputStream(jsonFile);
List<Product> products = new ArrayList<Product>();
products.add(new Product("0001", "Nexus S"));
products.add(new Product("0002", "谷歌眼镜"));
writeJsonStream(fos, products);
Toast.makeText(this, "成功保存JSON数据", Toast.LENGTH_LONG).show();
}
catch (Exception e)
{

}

}

public List<Product> readJsonStream(InputStream in) throws IOException
{
JsonReader reader = new JsonReader(new InputStreamReader(in, "UTF-8"));
try
{
return readProductArray(reader);
}

finally
{
reader.close();
}
}

public List readProductArray(JsonReader reader) throws IOException
{
List<Product> products = new ArrayList<Product>();

reader.beginArray();
while (reader.hasNext())
{
products.add(readProduct(reader));
}
reader.endArray();
return products;
}

public Product readProduct(JsonReader reader) throws IOException
{
String id = null;
String name = null;

reader.beginObject();
while (reader.hasNext())
{
String field = reader.nextName();

if (field.equals("id"))
{
id = reader.nextString();
}
else if (field.equals("name"))
{
name = reader.nextString();

}
else
{
reader.skipValue();
}
}
reader.endObject();
return new Product(id, name);
}

public void onClick_ReadJSON(View view)
{
try
{
FileInputStream fis = new FileInputStream(jsonFile);
List<Product> products = readJsonStream(fis);

if(products != null)
{
String result = "";
for(Product product: products)
{
result += "id:" + product.id + "  name:" + product.name + "\n";
}
Toast.makeText(this, result, Toast.LENGTH_LONG).show();
}
}
catch(Exception e)
{

}
}
}