小编Emm*_*rra的帖子

我试图从Firebase实时数据库中获取一些信息但没有成功.我不知道我做错了什么.我也尝试了doc的例子但它们没有用.这是我的代码和我的firebase db结构:

Topics.java:

public class Topics {

 private String name;

 public Topics() {

 }

 public Topics(String name) {
    this.name = name;
 }

 public String getName() {
    return name;
 }

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

}

Main.java

public static void main(String[] args) {
    // TODO Auto-generated method stub
    FileInputStream serviceAccount;
    FirebaseOptions options = null;
    try {
        serviceAccount = new FileInputStream(".//...");
        options = new FirebaseOptions.Builder()
                .setCredentials(GoogleCredentials.fromStream(serviceAccount))
                .setDatabaseUrl("...")
                .build();

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block …