Question

我想在JDBI 3（SQL对象）中执行SQL语句之前对其进行拦截和修改。这样做的原因是用架构名称替换自定义标记占位符。我找到了该线程，但它适用于JDBI 2（Using Dropwizard & JDBI to query database with multiple schemas?）。我尝试了下面的方法，但是在执行最终SQL查询之前就陷入了困境。

public class Product {
    private int id = -1;
    private String name = "";

    public Product() {
    }

    public Product(int id, String name) {
       this.id = id;
       this.name = name;
    }

    public int getId() {
       return this.id;
    }

    public void setId(int id) {
       this.id = id;
    }

    public String getName() {
       return this.name;
    }

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

public class ProductMapper implements RowMapper<Product> {

    @Override
    public Product map(ResultSet r, StatementContext ctx) throws SQLException {
        Product product = new Product();

        product.setId(r.getInt("id"));
        product.setName(r.getString("name"));

        return product;
    }
}

@SchemaRewriterFactory
@UseClasspathSqlLocator
public interface ProductDao {

    /**
    * The sql query is located in resources ([package]/listProducts.sql)
    * listProducts.sql: SELECT PRODUCT_ID ID, NAME FROM :schema.PRODUCTS
    * @return
    */
   @SqlQuery
   @RegisterRowMapper(ProductMapper.class)
   List<Product> listProducts();

}


@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@SqlStatementCustomizingAnnotation(SchemaRewriterFactory.SchemaRewriter.class)
public @interface SchemaRewriterFactory {

    public class SchemaRewriter implements SqlStatementCustomizerFactory {

        @Override
        public SqlStatementCustomizer createForMethod(Annotation annotation, Class<?> sqlObjectType, Method method) {
            return null;
        }

        @Override
        public SqlStatementParameterCustomizer createForParameter(Annotation annotation, Class<?> sqlObjectType, Method method, Parameter param, int index, Type paramType) {
            return null;
        }

        @Override
        public SqlStatementCustomizer createForType(Annotation annotation, Class<?> sqlObjectType) {
            return q -> q.addCustomizer(new StatementCustomizer() {

                @Override
                public void beforeBinding(PreparedStatement stmt, StatementContext ctx) throws SQLException {}

                @Override
                public void beforeExecution(PreparedStatement stmt, StatementContext ctx) throws SQLException {                          
                    System.out.println(stmt.toString());
                    //TODO: HOW DO I MODIFY SQL (REPLACE TOKENS - :schema) BEFORE IT GETS EXECUTED?
                }

                @Override
                public void afterExecution(PreparedStatement stmt, StatementContext ctx) throws SQLException { }


             });

        }

    }
}

我还发现此线程使用@Define（Dynamic Order in JDBI SQL Object Queries）处理自定义标签替换。如果可能，我希望避免在每次调用时传递额外的参数。任何帮助将不胜感激！

Answer 1

您可以为此使用StringTemplate。

/**
  * The sql query is located in resources ([package]/listProducts.sql)
  * listProducts.sql: SELECT PRODUCT_ID ID, NAME FROM <schemaName>.PRODUCTS
  * @return
*/
@SqlQuery
@RegisterRowMapper(ProductMapper.class)
List<Product> listProducts(@Define("schemaName") String schemaName);

请小心清除schemaName参数（可能的SQL注入）

如何在JDBI 3（SQL对象）中执行SQL语句之前对其进行修改

1 个答案: