java项目错误集锦（一）

最新推荐文章于 2021-08-20 16:45:06 发布

原创最新推荐文章于 2021-08-20 16:45:06 发布 · 756 阅读

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#spring #mybatis #mysql #springboot

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1、Could not read document: Can not deserialize instance of java.lang.String out of START_OBJECT token

org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not deserialize instance of java.lang.String out of START_OBJECT token at [Source: java.io.PushbackInputStream@6ba16079; line: 32, column: 5] (through reference chain: com.casstime.ec.cloud.order.values.order.query.OrderQueryParam["orderIds"]->java.util.ArrayList[0]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token at [Source: java.io.PushbackInputStream@6ba16079; line: 32, column: 5] (through reference chain: com.casstime.ec.cloud.order.values.order.query.OrderQueryParam["orderIds"]->java.util.ArrayList[0]) at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:228) ~[spring-web-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]

2、java.sql.SQLException: Unknown system variable 'query_cache_size'

mysql-connector-java.jar包版本不对，将版本换成8以上即可

3、java.sql.SQLException: The server time zone value 'ÖÐ¹ú±ê×¼Ê±¼ä' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

mysql时区错误，在url后边加上&serverTimezone=GMT%2B8即可

4、Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.

这里是在连接MYSQL时出现的SSL连接证书的问题，有两种解决方法

①、在数据库连接url中添加useSSL=false，即不使用SSL连接

spring.datasource.url=jdbc:mysql://localhost:3306/ux?&useSSL=false

②、使用SSL连接即在数据库连接url中添加useSSL=true，并提供服务器验证证书