The use of building blocks created a need for more lenient checking of exception throw lists compared to earlier SigTest tool versions. Consequently, SigTest tool 1.5 provides both a source and a binary compatibility mode of operation. This retains compatibility with earlier signature files while adding support for building blocks and eliminating the unnecessary error messages.

The SignatureTest command recognizes the -modeoption that takes the values “src” or “bin” as arguments for choosing source mode or binary mode. The choice of which mode to use depends on the type of signature file being used in the test.

This is described in more detail later in these sections:

Setup Command” on page 14 describes how to generate a signature file

SignatureTest Command” on page 20 describes how to specify the mode when running a signature test

Merge Command” on page 27 describes how to generate a combined signature file from set of signature files

The difference between the binary and source compatibility modes is how the tool handles the throws list for constructors and methods (as described in “Class and Class Member Attributes Checked” on page 3). Constant checking behavior is also different in binary and source compatibility modes. Although constant checking can be applied to binary compatibility, it is a necessary prerequisite for source code compatibility. “Constant Checking in Differing Run Modes” on page 9 describes these differences in more detail.

Using Custom Signature Loaders

The signature test has a requirement for the Java™ Platform, Standard Edition (Java SE platform) runtime environment version 1.4 or later. This requirement might prevent use of the tool on limited or nonstandard environments such as some Java™ Platform, Micro Edition (Java ME platform) or Java™ Platform, Enterprise Edition (Java EE platform) configurations.

To overcome this, the tool provides support for custom signature loaders that can be implemented as plug-ins. These plug-ins gather signatures from a runtime environment when the SignatureTest command cannot be run directly. For example, you might create a light-weight remote JavaTest harness agent and run the signature loader on a remote Connected Device Configuration (CDC) compatible device. Another example is using a wrapped J2EE platform bean as a signature loader inside a J2EE platform container where any direct file I/O operations are prohibited.

Chapter 1 Introduction

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Sun Microsystems 2 manual Using Custom Signature Loaders

2 specifications

Sun Microsystems, founded in 1982, was a significant player in the computing industry, best known for its innovative technology solutions and workstations, particularly the Sun-4, which represented a key milestone in the company's history. The Sun-4 architecture, launched in 1987, utilized the SPARC (Scalable Processor Architecture) RISC processor, notable for its high performance and scalability.

One of the primary features of Sun Microsystems' platforms was their ability to efficiently handle multitasking and resource management, making them ideal for enterprise-level applications and development environments. Sun-4 workstations boasted impressive graphics capabilities with the addition of advanced graphical user interfaces, support for color displays, and the SUNVIEW windowing system, which enhanced user experience and productivity.

The Sun-4 systems also supported the SunOS operating system, which was based on UNIX. This operating system was engineered for stability and robustness, offering features like multiuser support, networked environments, and advanced security options. Moreover, SunOS provided seamless integration with various programming languages, including C and C++, facilitating software development that aligned with industry standards.

Another standout characteristic of Sun Microsystems was its commitment to open systems and standards. By providing developers with comprehensive tools and environments, such as the Standardized Application Programming Interface (API) and support for networking protocols, Sun facilitated interoperability among different computing platforms. The emphasis on open architecture also meant that customers could easily upgrade their systems without being locked into proprietary solutions.

Sun Microsystems was also ahead of its time with innovations in network computing. Their workstations were among the first to support network file systems and distributed computing concepts, enabling seamless data sharing across multiple systems. With the introduction of the Network File System (NFS), Sun revolutionized how data was accessed and managed across networks, which played a significant role in the evolving landscape of client-server computing.

In summary, the Sun Microsystems 2 and its successive innovations in workstation technology highlighted the company's forward-thinking approach. By integrating powerful performance with open systems, robust operating systems, and advanced networking capabilities, Sun laid the groundwork for modern computing, influencing various sectors from academia to enterprise solutions. Even after its acquisition by Oracle in 2010, the legacy of Sun Microsystems continues to be felt across the computing industry.