用JAVA将多值文件加载到ArrayList中

Question

我有一个包含这样内容的文件：

accountNumber=1000，分支名称=‘11’，balance=420，customerNumber=1 accountNumber=1001，分支名称=‘11’，balance=323，customerNumber=2

我有一个读取内容并将其加载到ArrayList的方法，但是：

private static void loadAccounts() throws IOException, ClassNotFoundException {
static ArrayList<Account> accounts = new ArrayList<Account>();
    FileInputStream fileInputStream = new FileInputStream("AccountFile");
    ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
    accounts = (ArrayList<Account>) objectInputStream.readObject();
    objectInputStream.close();
}

但是，在我调用loadAccount()之后，我得到了以下错误：

线程"main“中的java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:938)异常:无效的流头: 6163636F在java.io.ObjectInputStream.(ObjectInputStream.java:396) at Main.loadAccounts at Main.loadAccounts(Main.java:151) at Main.main(Main.java:18)

Answer 1

Java没有自动将这些行转换为Account对象的解决方案，您需要自己实现它。假设线条模式没有改变，下面是如何使其工作的一个示例：

    private static void loadAccounts() throws IOException, ClassNotFoundException {
        List<Account> accounts = new ArrayList<Account>();
        final FileReader fileReader = new FileReader("AccountFile");
        final BufferedReader bufferedReader = new BufferedReader(fileReader);
        String line = bufferedReader.readLine();

        while ( line != null) {
            final String[] split = line.split(",");
            final Map<String, String> map = new HashMap<>();
            for (String entry : split) {
                final String[] keyAndValue = entry.split("=");
                map.put(keyAndValue[0], keyAndValue[1]);
            }
            Account account = new Account();
            account.setAccountNumber(map.get("accountNumber"));
            account.setBranchName(map.get("branchName"));
            account.setBalance(map.get("balance"));
            account.setBranchName(map.get("customerNumber"));
            
            accounts.add(account);
            line = bufferedReader.readLine();
        }

        fileReader.close();
        bufferedReader.close();
    }