![]() Although you can’t tell by just reading its method signature, the writeChars(String) method also writes its data in binary format rather than as a sequence of characters. However, note that the writeChar() takes an int parameter, which indicates that the character is written in binary format rather than as a ASCII or Unicode character. As you can see, there’s one method for each primitive type. 11.18), which contains a write() method for each different type of data. These kinds of methods are found in DataOutputStream (Fig. This class has the right kind of constructors, but it only contains write() methods for writing ints and bytes, and we need to be able to write Strings and doubles as well as ints. Because we’re outputting to a file, one likely candidate is FileOutputStream (Fig. and Table 11.1).īecause we are performing binary output, we need to use some subclass of OutputStream. That is, we start with two questions:Īnd we find the answers to these by searching through the java.io package (Fig. Our approach to designing this output method will be the same as the approach we used in designing methods for text I/O. Of course, when these data are stored in the file, or in the program’s memory, they just look like one long string of 0’s and 1’s. For example, the data in a file containing four records might look like this, once the data are interpreted: Name0 24 15.06Īs you can see, these data look as if they were randomly generated, but they resemble the real data in the important respects: They are of the right type- String, int, double-and have the right kind of values. Let’s assume that each record contains three individual pieces of data-the employee’s name, age, and pay rate. The first thing we need to know is exactly what the data look like. These can’t easily be built by hand-remember you can’t use a text editor to create them-so you’ll want to develop a method that can generate some random data of the sort your application will have to process. As the developer of this program, one thing you’ll have to do is build some sample data files. Let’s begin by designing a method that will output employee data to a binary file. The difference between text and binary file I/O resides in the Java streams that we use. Read or write the data, possibly using a loop. Generally speaking, the steps involved in reading and writing binary files are the same as for text files: A binary file doesn’t have an end-of-file character because any such character would be indistinguishable from a binary datum. Unlike a text file, which is terminated by a special end-of-file marker, a binary file consists of nothing but data. It’s like an object with no methods, just instance variables.Ī binary file is a sequence of bytes. Recall that a record is a structure that combines different types of data into a single entity. Suppose you are asked to write an application that involves the use of a company’s employee records. Files such as these must be processed as binary data. ![]() Similarly, a company’s inventory files, which also include data of a wide variety of types, cannot be processed as text. Because your student record contains a variety of different types of data- Strings, ints, doubles-it cannot be processed as text. For example, your college’s administrative data system undoubtedly uses files to store student records. Of course, this is only advised if you know what you're doing otherwise, you might corrupt the file for good.\)Īlthough text files are extremely useful and often employed, they can’t and shouldn’t be used for every data-processing application. This way, you'll be able to see the code content of the file and edit it. Ultimately, you can open any BIN file with a hex editor, such as Hexed, regardless of its purpose. Emulators such as DGen, Kega Fusion, and ePSXe use BIN files. If your BIN file is an old-school video game file, you can use it through the emulator. Video game emulators often use the BIN file format to mount games. Once you open the BIN file with an image tool, you can view its content and edit it to your liking. If that's the case, you can easily open it with image tools such as PowerISO. Your BIN file could be an image ripped from a CD or DVD. Here are the three major ways you can open a BIN file. As BIN files are used in an array of programs, you'll first need to figure out what the BIN file does. As mentioned before, properly opening a BIN file greatly depends on the file's purpose.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |