Sql exception class in java

Handling SQLExceptions

When JDBC encounters an error during an interaction with a data source, it throws an instance of SQLException as opposed to Exception . (A data source in this context represents the database to which a Connection object is connected.) The SQLException instance contains the following information that can help you determine the cause of the error:

• A description of the error. Retrieve the String object that contains this description by calling the method SQLException.getMessage .
• A SQLState code. These codes and their respective meanings have been standardized by ISO/ANSI and Open Group (X/Open), although some codes have been reserved for database vendors to define for themselves. This String object consists of five alphanumeric characters. Retrieve this code by calling the method SQLException.getSQLState .
• An error code. This is an integer value identifying the error that caused the SQLException instance to be thrown. Its value and meaning are implementation-specific and might be the actual error code returned by the underlying data source. Retrieve the error by calling the method SQLException.getErrorCode .
• A cause. A SQLException instance might have a causal relationship, which consists of one or more Throwable objects that caused the SQLException instance to be thrown. To navigate this chain of causes, recursively call the method SQLException.getCause until a null value is returned.
• A reference to any chained exceptions. If more than one error occurs, the exceptions are referenced through this chain. Retrieve these exceptions by calling the method SQLException.getNextException on the exception that was thrown.

Retrieving Exceptions

The following method, JDBCTutorialUtilities.printSQLException , outputs the SQLState, error code, error description, and cause (if there is one) contained in the SQLException as well as any other exception chained to it:

public static void printSQLException(SQLException ex) < for (Throwable e : ex) < if (e instanceof SQLException) < if (ignoreSQLException( ((SQLException)e). getSQLState()) == false) < e.printStackTrace(System.err); System.err.println("SQLState: " + ((SQLException)e).getSQLState()); System.err.println("Error Code: " + ((SQLException)e).getErrorCode()); System.err.println("Message: " + e.getMessage()); Throwable t = ex.getCause(); while(t != null) < System.out.println("Cause: " + t); t = t.getCause(); >> > > >

For example, if you call the method CoffeesTable.dropTable with Java DB as your DBMS, the table COFFEES does not exist, and you remove the call to JDBCTutorialUtilities.ignoreSQLException , the output will be similar to the following:

SQLState: 42Y55 Error Code: 30000 Message: 'DROP TABLE' cannot be performed on 'TESTDB.COFFEES' because it does not exist.

Instead of printing SQLException information, you could instead first retrieve the SQLState then process the SQLException accordingly. For example, the method JDBCTutorialUtilities.ignoreSQLException returns true if the SQLState is equal to code 42Y55 (and you are using Java DB as your DBMS), which causes JDBCTutorialUtilities.printSQLException to ignore the SQLException :

public static boolean ignoreSQLException(String sqlState) < if (sqlState == null) < System.out.println("The SQL state is not defined!"); return false; >// X0Y32: Jar file already exists in schema if (sqlState.equalsIgnoreCase("X0Y32")) return true; // 42Y55: Table already exists in schema if (sqlState.equalsIgnoreCase("42Y55")) return true; return false; >

Retrieving Warnings

SQLWarning objects are a subclass of SQLException that deal with database access warnings. Warnings do not stop the execution of an application, as exceptions do; they simply alert the user that something did not happen as planned. For example, a warning might let you know that a privilege you attempted to revoke was not revoked. Or a warning might tell you that an error occurred during a requested disconnection.

A warning can be reported on a Connection object, a Statement object (including PreparedStatement and CallableStatement objects), or a ResultSet object. Each of these classes has a getWarnings method, which you must invoke in order to see the first warning reported on the calling object. If getWarnings returns a warning, you can call the SQLWarning method getNextWarning on it to get any additional warnings. Executing a statement automatically clears the warnings from a previous statement, so they do not build up. This means, however, that if you want to retrieve warnings reported on a statement, you must do so before you execute another statement.

The following methods from JDBCTutorialUtilities.java illustrate how to get complete information about any warnings reported on Statement or ResultSet objects:

public static void getWarningsFromResultSet(ResultSet rs) throws SQLException < JDBCTutorialUtilities.printWarnings(rs.getWarnings()); >public static void getWarningsFromStatement(Statement stmt) throws SQLException < JDBCTutorialUtilities.printWarnings(stmt.getWarnings()); >public static void printWarnings(SQLWarning warning) throws SQLException < if (warning != null) < System.out.println("\n---Warning---\n"); while (warning != null) < System.out.println("Message: " + warning.getMessage()); System.out.println("SQLState: " + warning.getSQLState()); System.out.print("Vendor error code: "); System.out.println(warning.getErrorCode()); System.out.println(""); warning = warning.getNextWarning(); >>

The most common warning is a DataTruncation warning, a subclass of SQLWarning . All DataTruncation objects have a SQLState of 01004 , indicating that there was a problem with reading or writing data. DataTruncation methods let you find out in which column or parameter data was truncated, whether the truncation was on a read or write operation, how many bytes should have been transferred, and how many bytes were actually transferred.

Categorized SQLExceptions

Your JDBC driver might throw a subclass of SQLException that corresponds to a common SQLState or a common error state that is not associated with a specific SQLState class value. This enables you to write more portable error-handling code. These exceptions are subclasses of one of the following classes:

See the latest Javadoc of the java.sql package or the documentation of your JDBC driver for more information about these subclasses.

Other Subclasses of SQLException

The following subclasses of SQLException can also be thrown:

• BatchUpdateException is thrown when an error occurs during a batch update operation. In addition to the information provided by SQLException , BatchUpdateException provides the update counts for all statements that were executed before the error occurred.
• SQLClientInfoException is thrown when one or more client information properties could not be set on a Connection. In addition to the information provided by SQLException , SQLClientInfoException provides a list of client information properties that were not set.

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Class SQLException

An exception that provides information on a database access error or other errors.

• a string describing the error. This is used as the Java Exception message, available via the method getMessage .
• a «SQLstate» string, which follows either the XOPEN SQLstate conventions or the SQL:2003 conventions. The values of the SQLState string are described in the appropriate spec. The DatabaseMetaData method getSQLStateType can be used to discover whether the driver returns the XOPEN type or the SQL:2003 type.
• an integer error code that is specific to each vendor. Normally this will be the actual error code returned by the underlying database.
• a chain to a next Exception. This can be used to provide additional error information.
• the causal relationship, if any for this SQLException .

Constructor Summary

Method Summary

Methods declared in class java.lang.Throwable

Methods declared in class java.lang.Object

Methods declared in interface java.lang.Iterable

Constructor Details

SQLException

Constructs a SQLException object with a given reason , SQLState and vendorCode . The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method.

SQLException

Constructs a SQLException object with a given reason and SQLState . The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method. The vendor code is initialized to 0.

SQLException

Constructs a SQLException object with a given reason . The SQLState is initialized to null and the vendor code is initialized to 0. The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method.

SQLException

Constructs a SQLException object. The reason , SQLState are initialized to null and the vendor code is initialized to 0. The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method.

SQLException

Constructs a SQLException object with a given cause . The SQLState is initialized to null and the vendor code is initialized to 0. The reason is initialized to null if cause==null or to cause.toString() if cause!=null .

SQLException

Constructs a SQLException object with a given reason and cause . The SQLState is initialized to null and the vendor code is initialized to 0.

SQLException

Constructs a SQLException object with a given reason , SQLState and cause . The vendor code is initialized to 0.

SQLException

Method Details

getSQLState

getErrorCode

getNextException

setNextException

iterator

Returns an iterator over the chained SQLExceptions. The iterator will be used to iterate over each SQLException and its underlying cause (if any).

Report a bug or suggest an enhancement
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Copyright © 1993, 2023, Oracle and/or its affiliates, 500 Oracle Parkway, Redwood Shores, CA 94065 USA.
All rights reserved. Use is subject to license terms and the documentation redistribution policy.

Источник

Sql exception class in java

Constructs a SQLException object with a given reason , SQLState and vendorCode . The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method.

SQLException

Constructs a SQLException object with a given reason and SQLState . The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method. The vendor code is initialized to 0.

SQLException

Constructs a SQLException object with a given reason . The SQLState is initialized to null and the vendor code is initialized to 0. The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method.

SQLException

Constructs a SQLException object. The reason , SQLState are initialized to null and the vendor code is initialized to 0. The cause is not initialized, and may subsequently be initialized by a call to the Throwable.initCause(java.lang.Throwable) method.

SQLException

Constructs a SQLException object with a given cause . The SQLState is initialized to null and the vendor code is initialized to 0. The reason is initialized to null if cause==null or to cause.toString() if cause!=null .

SQLException

Constructs a SQLException object with a given reason and cause . The SQLState is initialized to null and the vendor code is initialized to 0.

SQLException

public SQLException(String reason, String sqlState, Throwable cause)

Constructs a SQLException object with a given reason , SQLState and cause . The vendor code is initialized to 0.

SQLException

public SQLException(String reason, String sqlState, int vendorCode, Throwable cause)

Method Detail

getSQLState

getErrorCode

getNextException

setNextException

iterator

Returns an iterator over the chained SQLExceptions. The iterator will be used to iterate over each SQLException and its underlying cause (if any).

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2023, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.

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