Package org.apache.derby.impl.services.stream

Class SingleStream

  • All Implemented Interfaces:
    java.security.PrivilegedAction<HeaderPrintWriter>, ModuleControl, InfoStreams
    public final class SingleStream
extends java.lang.Object
implements InfoStreams, ModuleControl, java.security.PrivilegedAction<HeaderPrintWriter>
    The Basic Services provide InfoStreams for reporting information. Two streams are provided: trace and error. It is configurable where these streams are directed.

    Errors will be printed to the error stream in addition to being sent to the client.

    By default both streams are sent to an error log for the system. When creating a message for a stream, you can create an initial entry with header information and then append to it as many times as desired.

    Note: if character encodings are needed, the use of java.io.*OutputStream's should be replaced with java.io.*Writer's (assuming the Writer interface remains stable in JDK1.1)

    • Constructor Detail

      • SingleStream

        public SingleStream()
        The no-arg public constructor for ModuleControl's use.

    • Method Detail

      • boot

        public void boot​(boolean create,
                 java.util.Properties properties)
        Description copied from interface: ModuleControl
        Boot this module with the given properties. Creates a module instance that can be found using the findModule() methods of Monitor. The module can only be found using one of these findModule() methods once this method has returned.

        An implementation's boot method can throw StandardException. If it is thrown the module is not registered by the monitor and therefore cannot be found through a findModule(). In this case the module's stop() method is not called, thus throwing this exception must free up any resources.

        When create is true the contents of the properties object will be written to the service.properties of the persistent service. Thus any code that requires an entry in service.properties must explicitly place the value in this properties set using the put method.
        Typically the properties object contains one or more default properties sets, which are not written out to service.properties. These default sets are how callers modify the create process. In a JDBC connection database create the first set of defaults is a properties object that contains the attributes that were set on the jdbc:derby: URL. This attributes properties set has the second default properties set as its default. This set (which could be null) contains the properties that the user set on their DriverManager.getConnection() call, and are thus not owned by Derby code, and thus must not be modified by Derby code.

        When create is false the properties object contains all the properties set in the service.properties file plus a limited number of attributes from the JDBC URL attributes or connection properties set. This avoids properties set by the user compromising the boot process. An example of a property passed in from the JDBC world is the bootPassword for encrypted databases.

        Code should not hold onto the passed in properties reference after boot time as its contents may change underneath it. At least after the complete boot is completed, the links to all the default sets will be removed.

        Specified by:
        boot in interface ModuleControl
        See Also:
        ModuleControl.boot(boolean, java.util.Properties)

      • stop

        public void stop()
        Description copied from interface: ModuleControl
        Stop the module. The module may be found via a findModule() method until some time after this method returns. Therefore the factory must be prepared to reject requests to it once it has been stopped. In addition other modules may cache a reference to the module and make requests of it after it has been stopped, these requests should be rejected as well.
        Specified by:
        stop in interface ModuleControl
        See Also:
        ModuleControl.stop()

      • makeStream

        private HeaderPrintWriter makeStream()
        Make the stream; note that service properties override application and system properties.

      • PBmakeFileHPW

        private HeaderPrintWriter PBmakeFileHPW​(java.lang.String fileName,
                                        PrintWriterGetHeader header)
        Make a header print writer out of a file name. If it is a relative path name then it is taken as relative to derby.system.home if that is set, otherwise relative to the current directory. If the path name is absolute then it is taken as absolute.

      • makeValueHPW

        private HeaderPrintWriter makeValueHPW​(java.lang.reflect.Member whereFrom,
                                       java.lang.Object value,
                                       PrintWriterGetHeader header,
                                       java.lang.String name,
                                       boolean canClose)

      • getMonitor

        private static ModuleFactory getMonitor()
        Privileged Monitor lookup. Must be private so that user code can't call this entry point.