Labs

The focus of this set of labs is reading, parsing, and writing files.

  1. Create a class named SearchEmployees that searches through the file employee.txt for the pattern "manager", and prints out any lines that match the pattern. (Hint: You can search through a string for a substring using the indexOf or contains methods in the String class.)

(Solution: SearchEmployees.java)

  1. Add code to PlanetReader to open planets.txt and read it one line at a time. As it reads each line, have it print just the planet's name. (Hint: String.split.)

(Solution: PlanetReader.java)

  1. Modify PlanetReader. After reading a record, it should use the fields to construct a Planet object, then print it using Planet's toString.

(Solution: PlanetReader2.java)

  1. Modify PlanetReader. In readPlanets add a local variable of type List<Planet> initialized with an ArrayList. While reading from the file, instead of printing the Planet, add it to the list. Change the readPlanets return type from void to List<Planet>, and return the list after the file is closed. In main, assign the returned list to a local variable and print it.

(Solution: PlanetReader3.java)

  1. Modify PlanetReader. Create a writePlanets method that takes a String filename and a List<Planet> parameter. It should open the named file for output, and for each planet, write its name, orbit, and diameter to the file, separated by tab (\t) characters. Make sure you don't use planets.txt as the output file name! Check the results in your output file by opening it with the Eclipse Text Editor (Hint: In Eclipse, when a program creates a file in your project, Eclipse won't notice and display it until you do a File | Refresh (or F5.)

(Solution: PlanetReader4.java)

planets.txt 

Mercury, 57910000, 4880
Venus, 108200000, 12103
Earth, 149600000, 12756
Mars, 227940000, 6794
Jupiter, 778330000, 142984
Saturn, 1429400000, 120536
Uranus, 2870990000, 51118
Neptune, 4504000000, 49532

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