Differences Between RPC And RMI

Differences Between RPC And RMI In enterprise application there is possibility that resources need to be access across multiple system to do a business process. One of the Javas solutions for distributed application is Remote Method Invocation (RMI). Objective of this paper is understand how a RMI system works in real time scenarios and how enterprise application can implemented using java RMI APIs. An enterprise distributed system is a set of objects that isolates the consumers of services from the providers of services by a well-defined interface. In other words, clients are completely abstracted from the implementation of business method as data structure and executable code. This is how one can distinguish with simple client / server application with object based remote invocation method model. In the distributed enterprise object model, a client sends a request message to an object, which in turns analyzes the request to decide what service to perform. This business entity service, selection could be performed by either the object or a broker. Remote Method Invocation (RMI): RMI is one of the possible ways to access distributed business objects from another JVM and RMI uses object serialization to marshal and unmarshal parameters. If you want send objects across the wire, your class (object) need to implements Serializable interface. Here is the RMI architecture and how RMI s works internally. RMI Transport Layer Client Server skeleton stub Interface Interface Client Process Server Process Process According to sun web site Java Remote Method Invocation (Java RMI) enables the programmer to create distributed Java technology-based to Java technology-based applications, in which the methods of remote Java objects can be invoked from other Java virtual machines*, possibly on different hosts. RMI uses object serialization to marshal and unmarshal parameters and does not truncate types, supporting true object-oriented polymorphism. When a enterprise server process wants to export some remote method invocation based service to consumer, it does so by registering remote method invocation enabled objects with its local rmiregistry (Registry interface). Every remote object is registered with a name consumer can use to reference it. A consumer can obtain a reference of stub to the remote object by requesting for the remote object by name through the Naming interface. The argument for Naming.lookup() method is name of a remote object and locates the object on the network. The objects fully qualified name can be composed with host name port and the name of the object look like url syntax for the naming resource. Few of the terminology one should know about RMI are listed below. rmiregistry A executable program used to bind remote object to names and that provides a bootstrap naming service which is used by servers on the server machine. JVMs on client and server machines can then look up remote objects and make remote method invocations. rmic: The rmic compiler tool generates stub, and skeleton class files for remote objects. These classes files are generated from the compiled Java language classes that contain remote object implementations (implemented java.rmi.Remote interface). skeleton : A skeleton for a remote object is a JRMP protocol server side business object that contains a method which dispatch calls to the actual remote object realization. stub: A proxy object for a remote object which is responsible for delegating method on remote objects to the server where implementation of the actual remote object resides. A consumer program reference to a remote object, therefore, is actually a reference to a local stub. Remote Interface: The Remote interface serves to recognize interfaces whose methods may be invoked from a non-local virtual machine. Any object that is a remote object must directly or indirectly implement this interface. Difference between RPC and RMI Remote procedure call (RPC) is a network communication protocol with server and client architecture and the idea behind RPC is to call implemented code remotely as if we were just calling a function. The only difference between RMI and RPC is in case of RPC functions are invoked through a proxy function, and in case of RMI we invoke methods through a proxy object. RMI is java solution to RPC, with connectivity to existing systems using native methods. RMI can take a natural, direct, and fully powered approach to provide a enterprise distributed computing technology that allows us to add Java functionality throughout the system. To get the cross-platform portability that Java provides, RPC requires a lot more overheads than RMI. RPC has to convert the arguments between architecture so that each computer can use its native data type. Java-RMI is tightly coupled with the Java language. Whereas RPC is not specific to any single language and one can implement RPC using different language. Because RMI can implemented using Java, its get all the advantages like object oriented, parallel computing, design pattern, easy to write and re use, safe and secure, Write once and run anywhere. But in the case of RPC, to achieve any of these advantages one has to write implementation code. Sample application: To demonstrate RMI and distributed application in real time I have implemented a Lottery system. The Lottery system is developed as per UK Lotto system. Assuming that user before using this RMI client application already purchased the lottery ticket. Lottery client system displays the welcome message to customer. Lottery system also displays the winning amount to the customer. The Lottery system is developed as per UK Lotto system. But simplifying system I have modified certain rules. Here how winner is chosen. Jackpot, Match 6: Â £500,000 Match 5 numbers: Â £1,500 Match 4 numbers: Â £60 Match 3 numbers: Â £10. System asks customer to enter positive integer number ranging 1 to 49. Once he enters all 6 numbers Lottery system generate 6 winning non-repeating random number between 1 to 49. System checks the match between user entered number and server generated number and calculate winning amount and display the result Implementation: Here is how I have implemented Lottery system Define a remote interface import java.rmi.Remote; public interface LotteryGenerator extends Remote { public ArrayList getLottoryNumber() throws java.rmi.RemoteException; } Implement the remote interface Below is the just a snippet of the implementation class for the remote interface. I have not listed the supporting private methods of the class. import java.rmi.RemoteException; public class LotteryGeneratorImpl extends java.rmi.server.UnicastRemoteObject implements LotteryGenerator{ private ArrayList numbers; // Integer array for holding repeat private ArrayList lot; private java.util.Random gen; public ArrayList getLottoryNumber(){ lot.clear(); for(int i=0;i

Chad Essay -- essays research papers

Chad Chad is one of the most underdeveloped countries in the world because of its climate, geographic location, and a lack of infrastructure and natural resources. It's main cash crop that is helping it's economy is cotton, which accounts for 48% of exports.1 The industry of Chad is mainly based on processing agricultural products. It is run by a republican government and it's legal system is based on French civil law system and Chadian customary law. The recent president is Idriss Deby and head of government is Prime Minister Joseph Yodoyman Chad had gained its independence from France on August 11, 1960. Its national holiday is held on the same day every year.   Ã‚  Ã‚  Ã‚  Ã‚  The geography of Chad is mostly pastures and meadows. Chad is located in Central Africa and is between the Central African Republic and Libya. The total area is 1,259,200 km2, and the land area is 1,259,200 km2.2 The total size in area of Chad is slightly more than three times the size of California. The land boundaries of Chad are; Cameroon (1,094 km), Central African Republic (1,197 km), Libya (1,055 km), Niger (1,175 km), Nigeria (87 km), and Sudan (1,360 km).3 All of these countries total to 5,968 km. Chad is landlocked which has no coastline. It has no marital claims. The disputes between Chad and other countries is that Libya claims and occupies the 100,000 km2 Aozou Strip in the far north. The year around climate is tropical in the south, and desert in the north. The terrain is broad, arid plains in the center, desert in the north, lowlands in the south and mountains in the northwest. The natural resources are petroleum, uranium, natron, kaolin, and fish. The land use consists of arable land (2%), permanent crops (0%), meadows and pastures (36%), forest and woodland (11%), and other (51%).4 The irrigated land used is 100km2. Its environment is hot, dry, dusty harmattan winds occur in the north, drought and desertification affecting much of the south, and subject to plagues of locusts.   Ã‚  Ã‚  Ã‚  Ã‚  The people of Chad rely on agriculture for survival. The total population is 5,350,971 people. The growth rate of the population is 2.13%. The birth rate is 42.21 births / 1,000 population. The death rate is 20.93 deaths / 1,000 population. The migration rate is 0% migrants / 1,000 population. Chad's death at infancy is at a great risk at 134 deaths ... ...s. The exchange rates are communaute Financiere Africaine Francs (CFAF per US $1 - 274.06 in January 1993, 264.69 in 1992, 282.11 in 1991, 272.26 in 1990, 319.01 in 1989, and 297.85 in 1988.8 Chad's fiscal year is a calendar year.   Ã‚  Ã‚  Ã‚  Ã‚  The highways in Chad total to 31,322 km, 32 km bituminous, 7,300 km gravel and laterite, and the remainder is unimproved earth.9 Inland waterways are 2,000 km navigable. Airports total to 69. The usable airports total to 55. Permanent-surface runways total to 5 airports. The telecommunications department in Chad is a fair system of radio communication stations for intercity links; broadcast stations - 6am, 1fm, limited television service; many facilities are inoperative; 1 Atlantic Ocean INTELSAT earth station.   Ã‚  Ã‚  Ã‚  Ã‚  Chad's defense forces consist of the branches, manpower, and defense expenditures. In the branches there is the Army and the Republican Guard. In the manpower availability males age from 15 to 49, total count is 1,246,617; fit for military service 647,908; reach military age is 20 and annually 52,870.10 In defense expenditures the exchange rate conversion is $58 million and 5.6% of GDP.

Shakespeare Sonnet Analysis

Nowak Enriched Language Arts 11 – Period 7 13 December 2011 Time: A Giver and Ravager Shakespeare uses tranquility, somberness, and hopefulness as elements of the mood in Sonnet 60. He begins the sonnet as a metaphor, â€Å"Like as the waves make towards the pebbled shore,† comparing time to a tide. Waves could represent peacefulness and one at ease because a tide is smooth and continuous. Later on the tone becomes more dark and depressive, â€Å"And time that gave doth now his gift confound. / Time doth transfix the flourish set on youth / And delves the parallels in beauty's brow† (9-10). Shakespeare expresses the fact that time gives the gift of life, but also takes it away with death while destroying nature’s perfection, â€Å"Feeds on the rarities of nature’s truth† (11). In the couplet, hope is seen because he says â€Å"And yet to times in hope my verse shall stand, / Praising thy worth, despite his cruel hand. † He anticipates that his words will not be destroyed by time and will continue to praise his beloved. The sonnet begins with tranquility, but then changes to somberness, yet Shakespeare still ends with words of hope. Shakespeare is telling the audience a lesson of time. Minutes are continuously coming, â€Å"So do our minutes hasten to their end† (2). He seems to be wrapped around the theme of time passing by and also trying to battle time, â€Å"Crooked elipses ‘gainst his glory fight† (7). Time can give yet also take, it is inevitable. It is the reason for birth, mortality, and change, but only words can withstand time. Imagery is a key peace to this insightful sonnet. The first line is an illustration to show time as the ocean â€Å"Like as waves make towards the pebbled shore. Using the sun to represent a human’s life, â€Å"Nativity, once in the main of light, / Crawls to maturity, wherewith being crown’d, / Crooked eclipses ‘gainst his glory fight. † Nativity is the birth, then one maturing into adulthood, and finally trying to fight or cheat death. He personifies time as it is passing in the couplet’s last words, â€Å"despite his cru el hand† (14). Time is the owner of the hand and the â€Å"cruel hand† is the elements of time. Mental images of Sonnet 60 are time passing, the cycle of life, and the personification of time. Shakespeare’s hope that his â€Å"verse shall stand,† (13) is now a fact. His message is being studied and analyzed in this assignment. This proves that even though his life has ended, his words of wisdom have defied time. Time does pass while giving and annexing life. It is ceaseless and unchanging. Everyone experiences time every day and because it is inescapable, Shakespeare expresses and characterizes time but its timelessness is why it is relevant to today. Works Cited Shakespeare, William. â€Å"Sonnet 60. † Shakespeare's Sonnets. Oxquarry Books Ltd. Web. 8 Dec. 2011. ;www. shakespeare-sonnets. com;

Female Priests And The Gender Inequality Within The...

Female priests and the gender inequality within the Catholic Church From the rampant persecution of science and inquiry during the Age of Enlightenment, to the condemnation of abortion and the use of contraceptives in the most HIV/AIDS ridden regions of Africa today, the Catholic Church has nearly always been the â€Å"thorn in the side† of progressive ideas, movements, organizations, and institutions. Today the Catholic Church remains one of the largest religious entities on the planet, with nineteen percent of the world’s population and a half of all Christians adhering to its religious doctrines (Catholic Desires for Change†). Catholicism is unique among Christian secs for its incredibly long history and staunch traditionalism. The church structure has remained almost unchanged since the time of the Roman Empire, and its doctrines are slow evolving at best. The Catholic Church only recently amended its stance on the heliocentric nature of the solar system, when in nineteen ninety two Pope John Paul II exonerated Galileo Galilei ’s crimes of heresy, three centuries after the man’s death (Cowell, 1992). As many western institutions begin to diversify their gender and ethnic makeup, the Catholic Church has remained almost devoid of female participation in all positions of authority and significance. The Church’s sedated progressivism has never been more egregious than in the rapidly changing society of the last half century, with the millennia old barriers of sexism rapidlyShow MoreRelated Utopia Essay1183 Words   |  5 Pageswell as social critique. Hythloday cannot stand the inequalities and injustices on the existing England and Europe and reveals possibilities for reform using his example of a Utopian society. The second part is written through the eyes of Hythloday and his explanation of the Utopian society of More. It serves as an improvement for where equity is offered. Some are very sensible while others are extremely extravagant. The major values raised within this text questioned perfection in society in mattersRead MoreFeminism1121 Words   |  5 Pagesdefined as a recognition and critique of male supremacy combined with efforts to change it. Feminism The goals of feminism are: To demonstrate the importance of women To reveal that historically women have been subordinate to men To bring about gender equity. Feminism Simply put: Feminists fight for the equality of women and argue that women should share equally in society’s opportunities and scare resources. Types Individualist feminism Relational Feminism (Karen Offen) History As old asRead MoreVoltaire s Candide : The Enlightenment Principle Of Reason1201 Words   |  5 PagesWithin the hundred or so pages of Voltaire’s Candide resides proof of all four values of the Enlightenment: hope, progress, natural law, and reason. Being a man of the enlightenment, it makes sense for Voltaire’s novel to include these values. Using ironic humor and satire, Voltaire managed to say what he needed to say without being directly responsible for having said it. As Candide reads like an adventure story, there is a lot of dialogue between characters. Through these conversations and storiesRead MoreModern Ireland: Why Did the Catholic Church Play Such a Prominent Role in Irish Life?2489 Words   |  10 PagesModern Ireland: Why did the Catholic Church play such a prominent role in Irish life in the middle years of the 20th Century? Introduction In the second and the third decades of the 20th century, there was high rate of unemployment in Ireland. During this time, most of the citizens also lived under poor and overcrowded conditions. These poor conditions enhanced the essence of emigration in the search for quality livelihood. During the fourth decade of the 20th century, there was a transformationRead MoreEssay about The Making of You as a Student1438 Words   |  6 Pages2011). This essay will discuss how a predominantly ‘Conservative’ orientation unintentionally shaped my childhood and adolescence, affected my views and expectations of sex and gender, and formed my idea of sexuality. I attended a Co-Educational Catholic School in Moree, New South Wales. Being a student at a Catholic school in a Cotton-growing town, the approach was one that took a majorly ‘Conservative’ orientation – so to fit inside the norms of society (Jones, 2009) and to abide by traditionalRead MoreThe Importance of Women Within Christianity2562 Words   |  11 PagesThe Importance of Women Within Christianity The role of women in Church has forever been scrutinized and misunderstood; although many churches continue to refuse women certain rights, it cannot be overseen the vast contributions women have given to Christianity and vice versa. All forms of Christianity use scriptures to guide their beliefs, theories and practices. For centuries it has been disputed and argued as to how scriptures should mold religious practices with changing times; with thisRead MoreThe Holy Book, The Bible, Torah And The Qur An1647 Words   |  7 PagesEve are created with the same similarity, however, man was made in the image of God, while the woman is made in the reflection of the man. Adding on, in Ephesians 5 it emphasizes â€Å"husbands love your wife, women are subordinate to your husbands† (catholic video). The only role a man has to his wife is to love her, however, a woman is expected to support her husband. Additionally, Judaism views creation in the same light as Christianity. Through J udith Plaskow interpretations â€Å"In the beginning, theRead MoreDiscuss the Contribution Feminism Has Made to Our Understanding of the Sociology of Religion. Illustrate Your Arguments with Sociological Examples.2539 Words   |  11 Pagesexamines the significance of the role of religion within society. It is not concerned with philosophical or theological issues such as the existence of God. Rather the sociology of religion examines how beliefs and practices affect behaviour, how religion is understood and how it influences social life. It also looks at the characteristics common to all religions and the factors which influence the way it is organised. Feminism is one area within sociology which takes a critical view of religionRead MoreGender Discrimination in the Elizabethan Era Essay1982 Words   |  8 PagesGender Discrimination was strongly evident in the Elizabethan Era between 1558 and 1603 with women ‘generally’ considered the inferior race and treated with subhuman actions based purely on their gender. Whilst is can be stated that women were treated wrongly is it fair to accuse the male men of that era with gender discrimination when it was what they were brought up to believe? Our morals and beliefs are derived from society’s general perception of right and wrong and in the Elizabethan Era itRead MoreWomen During Fascism The Temptress Vs The Model1842 Words   |  8 PagesThe latter, however, encapsulates the regime s efforts to boost population growth and to remove the women from competition with the men in the labor force. To depict these two female camps, both films oscillate between subjective and objective forms of camera work and uses characters dressing to reveal different female images. In Hitler Youth Quex, Steinhoff focuses on Gerda s legs and feet, while, Rossellini catches the body and facial expressions of Pina. Also, both film use the amorous dressing