http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2Ws/0c
} ~|B!.+
for(int i=0;i<nEndPos.length-1;i++) yM#trqv5
{ O^="T^J
nEndPos = nStartPos[i+1]; =R24h
} mj2sbRiSR=
nEndPos[nEndPos.length-1] = nFileLength; &G+:t)|S
} k0DX|O8mXV
} Lb2/ Te*
j0e1CSE
xkz`is77Y@
//启动子线程 mw=keY9]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Jz_`dLL^w
for(int i=0;i<nStartPos.length;i++) V ;M'd@
{ YccD^w[`B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lN::veD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 54&&=NVs|
nStartPos,nEndPos,i); ^eqq|(<K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !2]G.|5/A
fileSplitterFetch.start(); k5GJrK+
} rEZMX2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =ThacZHb8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pexg"328
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mv9@Az9
nEndPos = " + nFileLength); =)XC"kUp
// fileSplitterFetch[nPos.length-1].start(); "V7&@3
N6S}u@{J~N
k%ckV`y
//等待子线程结束 +P 9h%/Yk
//int count = 0; I!,FxOM|$
//是否结束while循环 0SWec7G
boolean breakWhile = false; :mz6*0qW
X9n},}bJ"
t{ScK%S6
while(!bStop) W-@}q}A
{ 0N*~"j;r#M
write_nPos(); {3=]cLtt
Utility.sleep(500); :+\B|*T2.L
breakWhile = true; n8>(m,
PaYsn *{})
Ycve[31BDd
for(int i=0;i<nStartPos.length;i++) >`c-Fqk
{ f\gN+4)
if(!fileSplitterFetch.bDownOver) M2e_)f:
{ p_2-(n@
breakWhile = false; {kgV3 [%>
break; ^iaG>rvA
} ?Dk&5d^d
} 8DP] C9
if(breakWhile) s@vHU4
break; oefhJM!y
!r*Ogv[
p$ %D
//count++; A~Ov(
//if(count>4) ?4,e?S6,[
// siteStop(); Dy_Za.N2
} 6{p]cr
qXJBLIG
X!%CYmIRb
System.err.println("文件下载结束！"); I+]q;dF;
} w8df-]r
catch(Exception e){e.printStackTrace ();} "eiZZSz
} ]ozZW:
~ g\GC
E/</
//获得文件长度 \]eB(&nq
public long getFileSize() ?|t9@r
{ .Bu?=+O~
int nFileLength = -1; H_<X\(
try{ z\fmwI
URL url = new URL(siteInfoBean.getSSiteURL()); b+.P4+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nDvj*lZF
httpConnection.setRequestProperty("User-Agent","NetFox"); q;p:)Q"
[80L|?, *
ny:4L{)
int responseCode=httpConnection.getResponseCode(); t_PAXj
if(responseCode>=400) }x^q?;7xW
{ ,s*-2Sz
processErrorCode(responseCode); ersddb^J]
return -2; //-2 represent access is error i+)9ItZr
} 8MH ZWi
BuE=(v2}
i,DnXgmz@
String sHeader; 9K\A4F}
H53dy*wb$
JlZU31Xws
for(int i=1;;i++) n-P)X<\
{ #3l&N4/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o+o'!)
//Utility.log(in.readLine()); `J%iFm/5*
sHeader=httpConnection.getHeaderFieldKey(i); b'Scoa7@'
if(sHeader!=null) )c:i'L
{ gn>qd6P
if(sHeader.equals("Content-Length")) Ps@a@d"83
{ 2nL[P#r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &> Myf@
break; xU4,Rcgo
} p<w2e
} p_x@FA(
else 3_:J`xX(4
break; biJ"@dm 4
} w^e5"og]
} dD Qx[
catch(IOException e){e.printStackTrace ();} SLyeonM-C
catch(Exception e){e.printStackTrace ();} }0&@J'<
/1F5khN
i/j DwA
Utility.log(nFileLength); =i_ s#v[Y
8CR b6
]m _<lRye
return nFileLength; K+=cNC4B
} r &<sSE;5
5C}1iZEJ
noali96J
//保存下载信息（文件指针位置） +j*hbG=
private void write_nPos() llbf(!
{ +K6j p
try{ ^EK]z8;|
output = new DataOutputStream(new FileOutputStream(tmpFile)); hG~TqH^}B
output.writeInt(nStartPos.length); A4lW8&rHI
for(int i=0;i<nStartPos.length;i++) oa4{s&db-
{ Y8c#"vm(
// output.writeLong(nPos); %r1NRg8
output.writeLong(fileSplitterFetch.nStartPos); UMcQqV+vT
output.writeLong(fileSplitterFetch.nEndPos); >l<`)4*H
} %XX(x'^4
output.close(); m&o6j>C
} 0X.(BRI~6p
catch(IOException e){e.printStackTrace ();} (!^i6z0Sp
catch(Exception e){e.printStackTrace ();} - '<K_e;
} :gD=F&V
avJ%J"j8z
,".1![b
//读取保存的下载信息（文件指针位置） b4Y<
private void read_nPos() %25GplMT
{ X+0+}S
try{ 2P`Z>_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 36 &ghx
int nCount = input.readInt(); Bri yy
nStartPos = new long[nCount]; uq.!{3)8
nEndPos = new long[nCount]; I&m C
for(int i=0;i<nStartPos.length;i++) }:04bIaV
{ sbeS9vE
nStartPos = input.readLong(); 25NTtj:X
nEndPos = input.readLong(); {WYJQKs8
} ';>]7oT`
input.close(); &xAwk-{W
} l2Gtw*i_I
catch(IOException e){e.printStackTrace ();} 0bl?dOV{
catch(Exception e){e.printStackTrace ();} %<^IAMkp
} +4*3aWf`
#N?VbDK9_
|\#~
private void processErrorCode(int nErrorCode) kYW>o}J|
{ _l{`lQ}
System.err.println("Error Code : " + nErrorCode); "!g}Q*
} bfE4.YF
'<Fr}Cn
|c<h&p
//停止文件下载 Whd\Ub8(
public void siteStop() [3@Pu.-I+M
{ Y8%bk2
bStop = true; 5YZh e4R
for(int i=0;i<nStartPos.length;i++) [C>>j;q%
fileSplitterFetch.splitterStop(); R^hlfKnt
~/QzL.S;p
JPmW0wM
} h"j{B
} >*EcX3
//负责部分文件的抓取 Tf` ~=fg%
**FileSplitterFetch.java ]@Q14
*/ Wa , #
package NetFox; e)O6k7U$
!x[+rf
iGM-#{5
import java.io.*; st~f}w@
import java.net.*; *ZAue.
iYR8sg[' #
j$BM$q/c
public class FileSplitterFetch extends Thread { H>k=V<
iN<Tn8-YH6
flnoK%wi
String sURL; //File URL UfXqcyY(
long nStartPos; //File Snippet Start Position YaDr6)
long nEndPos; //File Snippet End Position ^~?VD
int nThreadID; //Thread's ID A6= Um%T
boolean bDownOver = false; //Downing is over 5)nm6sf
boolean bStop = false; //Stop identical [T.kwQf4$
FileAccessI fileAccessI = null; //File Access interface #X`j#"Ov2(
^|(F|Z
?=-18@:.ss
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y}Y2Vx
{ eE+zL~CE
this.sURL = sURL; :k#Y|(
this.nStartPos = nStart; ,a_\o&V
this.nEndPos = nEnd; X*/jna"*
nThreadID = id; &dH/V-te
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KYZ/b8C
} C5$1K'X@
eE '\h
,)[u<&
public void run() $b QD{ {
{ mY+Jju1
while(nStartPos < nEndPos && !bStop) /z.Y<xOc
{ /q0[T{Wz$
#"|</*%>
mR)Xq=
try{ AQw1,tGV
URL url = new URL(sURL); .i) H1sD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z1{kZk
httpConnection.setRequestProperty("User-Agent","NetFox"); qH1[BsOx
String sProperty = "bytes="+nStartPos+"-"; ]6bh#N;.
httpConnection.setRequestProperty("RANGE",sProperty); N7v7b<6
Utility.log(sProperty); `A_CLVE
9nN$%(EO5;
J^m#984
InputStream input = httpConnection.getInputStream(); -~n^?0
//logResponseHead(httpConnection); ~oWCTj-
["TUSf]
j^-E,YMC
byte[] b = new byte[1024]; M_lQ^7/
int nRead; !<BJg3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ">_<L.,I
{ ND $m|V-C
nStartPos += fileAccessI.write(b,0,nRead); FrT.<3
//if(nThreadID == 1) +m8CN(c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |Ii[WfFA|J
} a~ sU
a|?&
(&t741DN|
Utility.log("Thread " + nThreadID + " is over!"); o b;]
bDownOver = true; s\O4D*8
//nPos = fileAccessI.write (b,0,nRead); Jmg<mjq/G
} *'[8FZ|dQ
catch(Exception e){e.printStackTrace ();} <q\OREMsq
} HEh,Cf7`'
} tQ~vLPi$
rHYSS0*3
r:;nv D
//打印回应的头信息 5^lFksZ
public void logResponseHead(HttpURLConnection con) l Oxz&m
{ J,q6
for(int i=1;;i++) @N+ }cej
{ <5@VFRjc
String header=con.getHeaderFieldKey(i); y#tuwzE
if(header!=null) E&>3{uZI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^EtBo7^t
Utility.log(header+" : "+con.getHeaderField(header)); 8[v9|r
else (dvsGYT|.
break; 0ndk=V
} b-!+Q)
} <9f;\+zA
@}K|/
>%6a$r~@
public void splitterStop() /Uxp5 b h
{ +;#z"m]
bStop = true; z3Id8G&>
} Z01BzIsR
2bv/-^
<DeC^[-P
} l7T@<V
lKVV*RR}
ce56$L8[
/* [KcF0%a
**FileAccess.java ;r8< Ed
*//文件访问(定位，写) zjE|UK{
package NetFox; +4 W6{`
import java.io.*; eeMeV>
#3~hF)u&/
PP*',D3
public class FileAccessI implements Serializable{ fvE:'( #?
1ze\ U>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3aY^6&
RandomAccessFile oSavedFile; 6lAHB*`
long nPos; #r,LV}*qg
n9H4~[JiC
{,X}Btnwp
public FileAccessI() throws IOException c3__=$)'kP
{ [ !<
this("",0); XM#xxf* Y
} Ht,+KbB
q?##S'
xg.o7-^M
public FileAccessI(String sName,long nPos) throws IOException {t%Jc~p{
{ 5 (cgHr"
oSavedFile = new RandomAccessFile(sName,"rw"); 2kSN<jMr
this.nPos = nPos; OD8{ /7
oSavedFile.seek(nPos); $S'~UbmYU
} qdNt2SO
DG-XX.:z
I xk+y?
public synchronized int write(byte[] b,int nStart,int nLen) Ri<'apl
{ zL@FN sYVM
int n = -1; PdD,~N#
try{ ))xP]Muv
oSavedFile.write(b,nStart,nLen); $6DA<v^=z
n = nLen; TbQ5
} eqQ=HT7J
catch(IOException e) _`~\zzUZ
{ L ]Y6/Q
e.printStackTrace (); %8c2d
} ,!>1A;~wT
7^FJ+gN8b
o>jM4sk$
return n; :~wU/dEEiz
} Wi2Tg^
I3hN7
Iw[7;B5v
} xcM*D3
]t)#,'$^[W
7GDrH/yK
/* vE{L`,\q
**SiteInfoBean.java _eZ*_H,\
*/ L_O*?aaZ
package NetFox; GyQ9we~
|w+N(wcJ
=-%10lOI
public class SiteInfoBean { U#6<80Ke
yFY:D2
M]7>Ar'zsG
private String sSiteURL; //Site's URL PHR:BiMZ
private String sFilePath; //Saved File's Path %3Tz%>n
private String sFileName; //Saved File's Name +Es3iE @
private int nSplitter; //Count of Splited Downloading File Rg<y8~|'}
N:0/8jmmO
G9z Q{E
public SiteInfoBean() =r+u!~%@''
{//nSplitter的缺省值为5 ?)Z~H,Q(z
//default value of nSplitter is 5 {~16j"
this("","","",5); v;el= D
} CY)Wuv ^
?F*gFW_k
E8jdQS|i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )Be}Ev#)Zx
{ %&Z!-k(
sSiteURL= sURL; U?>P6p
sFilePath = sPath; VyCBJK
sFileName = sName; ; z:}OD
this.nSplitter = nSpiltter; -#3B>VY
\PU|<Ru.
=4 &9!Z
} fcr\XCG7U
+q) ^pCC
Cf<i"
public String getSSiteURL() p8[Z/]p
{ RNcHU
return sSiteURL; }_3<Q\j
} lj@c"Yrk
`P)atQ
q3T'rw%Eh
public void setSSiteURL(String value) 1`5d~>fV
{ Th`IpxV
sSiteURL = value; \W(C=e
} a5?Rj~h!<
xV~`sqf
pUYa1=
public String getSFilePath() wR@fB
{ 4B-v\3Ff
return sFilePath; wCkhE,#-_
} ,X+mXtg.
fJd!;ur)0
cDxjD5E
public void setSFilePath(String value) w \i#
{ -1:yqF.x
sFilePath = value; yZJR7+
} (orO=gST-/
|Rk$u
z.itVQs$I
public String getSFileName() 86(8p_&zC
{ _+z5~6>
return sFileName; {bB;TO<b`
} 4#H~g @
ghq#-N/t
yeQ6\yi
public void setSFileName(String value) ptXCM[Z+
{ u'"VbW3u n
sFileName = value; lqPzDdC^>
} tm27J8wPzV
}$-;P=k
871taL=
public int getNSplitter() p]z *
{ ! Ff/RRo
return nSplitter; 0_7A <
} 5"1kfB3v
cnfjOg'\{
C^>txui8
public void setNSplitter(int nCount) 5AV5`<r.
{ <C0~7]XO
nSplitter = nCount; 5e^t;
} (gd+-o4
} ]mEY/)~7
S+LE ASOr
[0v`E5
/* vvEr}G
**Utility.java gc|?$aE
*/ ^(5Up=.EA
package NetFox; 'urn5[i
CT1)tRN
\bJ,8J1C
public class Utility { 34lt?6%j
~s_n\r&23
)@"iWQ3K
public Utility() ":t'}Eg=6
{ r=8(n<;Co
d^5OB8t
pa1.+~)
} ")%)e;V3
R7xKVS_MP
//线程睡眠 }*4K{<02
public static void sleep(int nSecond) # fvt:iE
{ \nQV{J
try{ {Vy2uow0
Thread.sleep(nSecond); .QRa{l_)
} H=2sT+Sp
catch(Exception e) Y](kMNUSg
{ j*uc$hC"
e.printStackTrace (); 7g'jg7
} Jb. V4
} 7A!E~/nSC
MXy~kb&
//日志 9d7`R'
public static void log(String sMsg) JO*}\Es
{ n)]]g3y2
System.err.println(sMsg); yb)!jLnH
} ZH]n&%@j
19.+"H
_ ^5w f
public static void log(int sMsg) /yRP>CX~
{ s d-5AE
System.err.println(sMsg); |3tq.JU
} *AEN
} r*e<`Is
}bwH(OOS
.Sz<%d7XIQ
/* N@Ie VF
**TestMethod.java g=8}G$su{%
*/ 9 U6cM-p?
package NetFox; !3]}3jZ.
dEz7 @T
xx^7
public class TestMethod { XJ\j0
Mp8BilH-T
zqd_^
public TestMethod() nYfZ[Q>v
{ ///xx/weblogic60b2_win.exe ;xp^FKP
try{ K,pQ11J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B2}|b^'I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 58T<~u7
SiteFileFetch fileFetch = new SiteFileFetch(bean); )vO?d~x|
fileFetch.start(); FQc8j:'
} -Re4G78%
catch(Exception e){e.printStackTrace ();} }Xn5M&>?
Gag=GHG
PP~rn fE
} V=He_9B
/iNa'W5\
5 8-e^.
public static void main(String[] args) v[@c*wo
{ YIt& >
new TestMethod(); L9Z;:``p
} n,HE0Zn]Y_
} X{n- N5*
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