Question

在一个项目中，我使用jklingsporn vertx-jooq作为jooq-CodeGenerator来创建异步的vertxified DAO和POJOS。我有一个生成的ContractDao.java类

import io.vertx.core.Future;
import io.github.jklingsporn.vertx.jooq.classic.async.AsyncClassicQueryExecutor;

/**
 * This class is generated by jOOQ.
 */
@Generated(value = { "http://www.jooq.org", "jOOQ version:3.10.6" }, comments = "This class is generated by jOOQ")
@SuppressWarnings({ "all", "unchecked", "rawtypes" })
public class ContractDao extends AbstractAsyncVertxDAO<ContractRecord, jooq.tables.pojos.Contract, Long, Future<List<jooq.tables.pojos.Contract>>, Future<jooq.tables.pojos.Contract>, Future<Integer>, Future<Long>> implements io.github.jklingsporn.vertx.jooq.classic.VertxDAO<ContractRecord, jooq.tables.pojos.Contract, Long> {

    /**
     * @param configuration
     *            Used for rendering, so only SQLDialect must be set and must be one
     *            of the MYSQL types or POSTGRES.
     * @param delegate
     *            A configured AsyncSQLClient that is used for query execution
     */
    public ContractDao(Configuration configuration, io.vertx.ext.asyncsql.AsyncSQLClient delegate) {
        super(Contract.CONTRACT, jooq.tables.pojos.Contract.class, new AsyncClassicQueryExecutor<ContractRecord, jooq.tables.pojos.Contract, Long>(configuration, delegate, jooq.tables.pojos.Contract::new, Contract.CONTRACT));
    }
  ....

 }

使用生成的Contract.java pojo类和BigDecimal字段。

/**
 * This class is generated by jOOQ.
 */
@Generated(
    value = {
        "http://www.jooq.org",
        "jOOQ version:3.10.6"
    },
    comments = "This class is generated by jOOQ"
)
@SuppressWarnings({ "all", "unchecked", "rawtypes" })
public class Contract implements VertxPojo, IContract {

    ...
    private BigDecimal costValue;
    ...

}

然后在vert.x Verticle类中，我有一个方法fetchContracts：

    private void fetchContracts(final Message<Void> msg) {
        contractDao.findAll().setHandler(arContracts -> {
            ...
        });
    }

到目前为止，它仍然可以正常工作，但是如果我在“表合同”字段中的costValue中有一个数值，则在我调用fetchContracts方法时会出现异常

java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Number

我猜有某种数据类型不匹配。我了解，如果我理解正确的话，可以通过数据类型强制或强制转换来解决此问题，如下所示：Casting org.jooq.TableField<Long> to org.jooq.TableField<BigDecimal>

但是在这种特殊情况下，我不清楚应该在哪里以及如何进行投射。

我尝试过类似的事情：

    private void fetchContracts(final Message<Void> msg) {
        jooq.tables.Contract.CONTRACT.COST_VALUE.coerce(String.class);
        contractDao.findAll().setHandler(arContracts -> {
            ...
        });
    }

但是它不起作用。任何想法？预先感谢。

编辑：

我添加了堆栈跟踪：

[ERROR] 2018-08-07 09:42:54,368: java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Number ( de.bfft.licencemgmt.server.UserVerticle.lambda$100(UserVerticle.java:998)) [vert.x-eventloop-thread-1]  []
[ERROR] 2018-08-07 09:42:54,368: (RECIPIENT_FAILURE,500) java.lang.String cannot be cast to java.lang.Number ( de.bfft.licencemgmt.client.viewslogic.agreements.AgreementsViewLogic.lambda$6(AgreementsViewLogic.java:61)) [vert.x-eventloop-thread-4]  []
[ERROR] 2018-08-07 09:42:54,368: Failed to handleMessage. address: 1 ( io.vertx.core.eventbus.impl.HandlerRegistration.deliver(HandlerRegistration.java:228)) [vert.x-eventloop-thread-4]  []
java.lang.NullPointerException: null
    at com.vaadin.server.AbstractExtension.extend(AbstractExtension.java:77) ~[vaadin-server-8.4.4.jar:8.4.4]
    at com.vaadin.ui.Notification.show(Notification.java:502) ~[vaadin-server-8.4.4.jar:8.4.4]
    at de.bfft.licencemgmt.client.viewslogic.agreements.AgreementsViewLogic.lambda$0(AgreementsViewLogic.java:39) ~[classes/:?]
    at io.vertx.core.impl.FutureImpl.tryFail(FutureImpl.java:165) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.impl.FutureImpl.fail(FutureImpl.java:97) ~[vertx-core-3.5.1.jar:3.5.1]
    at de.bfft.licencemgmt.client.viewslogic.agreements.AgreementsViewLogic.lambda$6(AgreementsViewLogic.java:62) ~[classes/:?]
    at io.vertx.core.eventbus.impl.EventBusImpl.lambda$convertHandler$1(EventBusImpl.java:349) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.eventbus.impl.HandlerRegistration.deliver(HandlerRegistration.java:223) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.eventbus.impl.HandlerRegistration.handle(HandlerRegistration.java:200) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.eventbus.impl.EventBusImpl.lambda$deliverToHandler$3(EventBusImpl.java:533) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.impl.ContextImpl.lambda$wrapTask$2(ContextImpl.java:339) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:463) [netty-transport-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171]
[ERROR] 2018-08-07 09:42:54,383: Unhandled exception ( io.vertx.core.impl.ContextImpl.lambda$wrapTask$2(ContextImpl.java:345)) [vert.x-eventloop-thread-4]  []
java.lang.NullPointerException: null
    at com.vaadin.server.AbstractExtension.extend(AbstractExtension.java:77) ~[vaadin-server-8.4.4.jar:8.4.4]
    at com.vaadin.ui.Notification.show(Notification.java:502) ~[vaadin-server-8.4.4.jar:8.4.4]
    at de.bfft.licencemgmt.client.viewslogic.agreements.AgreementsViewLogic.lambda$0(AgreementsViewLogic.java:39) ~[classes/:?]
    at io.vertx.core.impl.FutureImpl.tryFail(FutureImpl.java:165) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.impl.FutureImpl.fail(FutureImpl.java:97) ~[vertx-core-3.5.1.jar:3.5.1]
    at de.bfft.licencemgmt.client.viewslogic.agreements.AgreementsViewLogic.lambda$6(AgreementsViewLogic.java:62) ~[classes/:?]
    at io.vertx.core.eventbus.impl.EventBusImpl.lambda$convertHandler$1(EventBusImpl.java:349) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.eventbus.impl.HandlerRegistration.deliver(HandlerRegistration.java:223) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.eventbus.impl.HandlerRegistration.handle(HandlerRegistration.java:200) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.eventbus.impl.EventBusImpl.lambda$deliverToHandler$3(EventBusImpl.java:533) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.vertx.core.impl.ContextImpl.lambda$wrapTask$2(ContextImpl.java:339) ~[vertx-core-3.5.1.jar:3.5.1]
    at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:463) [netty-transport-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [netty-common-4.1.19.Final.jar:4.1.19.Final]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171]

以及导致UserVerticle.java类中异常的代码，堆栈跟踪中的998行对应于“ log.error（arContracts.cause（））”下面的第三行：

    private void fetchContracts(final Message<Void> msg) {
        contractDao.findAll().setHandler(arContracts -> {
            if (arContracts.failed()) {
                log.error(arContracts.cause());
                msg.fail(500, arContracts.cause().getMessage());
                return;
            }
            final List<Contract> contracts = arContracts.result();

            log.debug("Found {} contracts", contracts.size());
            final JsonArray jsonArray = new JsonArray(
                    contracts.stream().map(contract -> contract.toJson()).collect(Collectors.toList()));
            msg.reply(jsonArray);
        });
    }

Answer 1

问题出在json中十进制的转换中。 Json自动将十进制数字转换为字符串，但它期望使用十进制数字，从而以某种方式引发了异常

事实证明，还有一个CustomVertxGenerator.java类，该类扩展了vert.x-jooq的ClassicAsyncVertxGenerator，并提供了一种在JSON转换期间处理String中其他类型的方法。这对我来说是新的。

在该类的方法中将postgresql db中的数字类型的转换固定后，问题得以解决。

jooq java.lang.CastException：无法将java.lang.String强制转换为java.lang.Number

1 个答案: