Gson 使用 proguard 在 android 上解析

Gson parsing on android with proguard

我只有在使用 proguard 时才会遇到 Gson 的解析问题。在没有混淆器的调试模式和发布模式下,一切正常。

这是我的 json 字符串:

{"tables":[{"name":"Profile","columns":[{"label":"id","type":"text","primary":true},{"label":"name","type":"text"},{"label":"age","type":"integer"},{"label":"human","type":"integer"},{"label":"gear","type":"Gear","custom":true,"list":true}]},{"name":"Gear","columns":[{"label":"id","type":"text","primary":true},{"label":"type","type":"text","enum":true},{"label":"name","type":"text"},{"label":"id_Profile","type":"integer","foreign_key":true}]},{"name":"Animal","columns":[{"label":"id","type":"text","primary":true},{"label":"name","type":"text"},{"label":"magic","type":"integer"},{"label":"id_Profile","type":"integer","foreign_key":true}]}]}

这些是我的 POJO :

public class Database {
    private List<Table> tables;

    public List<Table> getTables() {
        return tables;
    }

    public void setTables(List<Table> tables) {
        this.tables = tables;
    }
}

public class Table {
    private String name;
    private List<Column> columns;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<Column> getColumns() {
        return columns;
    }

    public void setColumns(List<Column> columns) {
        this.columns = columns;
    }
 }

我读取了包含 json 字符串的文件并以这种方式解析它:

public Database getDatabase(Context context) throws IOException {
    InputStream stream = context.getAssets().open(PATH);
    String schema = getJsonSchema(stream);
    Gson gson = new Gson();
    return gson.fromJson(schema, Database.class);
}

但是当我尝试从我的 Database 对象调用方法 getTables() 时:

for (Table table : database.getTables()) {
    //...
}

我收到此错误:java.lang.NullPointerException: Attempt to invoke interface method 'java.util.Iterator java.util.List.iterator()' on a null object reference。我已经将那些 rules 包含在混淆器中。知道是什么原因吗?

正如达尔文评论的那样,将 @Keep 注释添加到我的 POJO 类 解决了问题