Spring-如何从application.properties中的spring.datasource配置OracleDataSource

Question

In my application.properties i have some spring.datasource fields

spring.jpa.database-platform=org.hibernate.dialect.Oracle10gDialect
spring.datasource.url=jdbc:oracle:thin:@localhost:1521:XE
spring.datasource.username=talon
spring.datasource.password=talon

These should be retrieved from a @Configuration annotated class

@Configuration
public class Db {

    @NotNull
    private String username;
    @NotNull
    private String password;
    @NotNull
    private String url;

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public Db() {
        OracleDataSource dataSource = null;
        try {
            dataSource = new OracleDataSource();
            dataSource.setUser(username);
            dataSource.setPassword(password);
            dataSource.setURL(url);
            dataSource.setImplicitCachingEnabled(true);
            dataSource.setFastConnectionFailoverEnabled(true);
            Connection connection = dataSource.getConnection();
            Statement statement = connection.createStatement();
            ResultSet rs = statement.executeQuery("select * from BOOK");
            rs.next();
            System.out.println(rs.getString(2));
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}

But I'm unable to retrieve the username password and url from there, should I add another annotation somewhere or what am I doing

Like this I have the error: java.sql.SQLException: Invalid Oracle URL specified: OracleDataSource.makeURL

If I set the proper url with dataSource.setURL("jdbc:oracle:thin:@localhost:1521:XE"); it can't read the username and password since they are null and I have java.sql.SQLException: ORA-01017: invalid username/password; logon denied

Answer 1

You have two issues:

1. You need to use another annotation in order for your fields to be populated. So annotate the class with @ConfigurationProperties("spring.datasource")

2. You cannot initialize your OracleDataSource directly in your constructor (ie Db() ) because the properties (your username/password/url fields) are not populated during the call of the constructor, so one thing that you can do is create another method and annotate that with @PostContruct in order for your dataSource to be correctly created.

An example:

@PostConstruct
private void init() {
    // your data source initialization

}

One advice would be to change the way to initialize your dataSource and instead of trying to create it inside your constructor, you can rather create a new method which you can annotate with @Bean and make it return your dataSource and you can use it later using @Autowired .