本文共 1319 字，大约阅读时间需要 4 分钟。
我有一个包含自定义服务对象的ArrayList.我想将整个ArrayList写入一个文件,然后可以读取它.
我为此尝试了Gson,但它给了我一个IllegalStateException：预期为BEGIN_ARRAY,但为STRING.我让它记录了应该是JSON的Strings,并在其中表示了很多异常(作为String中的文本..也许转换出错了吗？).
public int saveListToFile(){
String filename = "service_entries";
File file = new File(getFilesDir(), filename);
try {
BufferedWriter buffWriter = new BufferedWriter(new FileWriter(file, true));
Gson gson = new Gson();
String json = gson.toJson(services); //this is the ArrayList
buffWriter.append(json);
buffWriter.newLine();
buffWriter.close();
} catch (IOException e) {
return -1;
}
return 0;
}
public int readCurrentList(){
String filename = "service_entries";
File file = new File(getFilesDir(), filename);
try {
BufferedReader buffReader = new BufferedReader(new FileReader(file));
String line1, line2;
Gson gson = new Gson();
line1 = buffReader.readLine();
line2 = buffReader.readLine();
if(line1 == null){
buffReader.close();
return 0;
}
Type type = new TypeToken>(){}.getType();
services = gson.fromJson(line1, type);
ArrayList list2;
if(line2 != null){
list2 = gson.fromJson(line2, type);
services.addAll(list2);
list2 = null;
}
buffReader.close();
} catch(IOException e){
return -1;
}
return 0;
}
public class Service {
private double quantity;
private String description;
public Service(){
quantity = 0.0;
description = null;
}
}
转载地址：http://qhrdy.baihongyu.com/