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)); l\q*%'Pe
} 6"BtfQ")
for(int i=0;i<nEndPos.length-1;i++) Q&oC]u(="&
{ j9{O0[v
nEndPos = nStartPos[i+1]; ^>3tYg&7
} |z.Gh1GCy
nEndPos[nEndPos.length-1] = nFileLength; $ \? N<W
} l[tY,Y:4qO
} Dm7Y#)%8
5LDQ^n
6H(fk1E
//启动子线程 Xg|8".B)A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D+bB G
for(int i=0;i<nStartPos.length;i++) Nr>c'TH
{ %4bO_vb<9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LXBbz;vYl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #JK;&Dg!
nStartPos,nEndPos,i); ;k9 ?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yd7lcb [
fileSplitterFetch.start(); p:DL:^zx
} Y}AmX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3!i.Fmo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gg 7WmL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jA20c(O
nEndPos = " + nFileLength); y0/WA4,
// fileSplitterFetch[nPos.length-1].start(); lcu("^{3
FQ;4'B^k]
BNAguAxWo
//等待子线程结束 #E- VW
//int count = 0; 1x~%Ydy
//是否结束while循环 KzEuPJ?
boolean breakWhile = false; bYwI==3
zvek2\*rO
Q'n(^tbL
while(!bStop) 4+ASwN9
{ oUW)H
write_nPos(); nz,Mqol
Utility.sleep(500); >i^y;5
breakWhile = true; -X"5G
tYI]LL
$nUd\B$.=
for(int i=0;i<nStartPos.length;i++) 6{JR0
{ k#1`
if(!fileSplitterFetch.bDownOver) *u|lmALs
{ >P6^k!R1y
breakWhile = false; /'8*aUa
break; Uq<a22t@
} )GiFkG
} Y9IJ
if(breakWhile) Cm,*bgX
break; ltCwns
%8}WX@SB
ua]\xBWx
//count++; (SgEt
//if(count>4) \Dvl%:8
// siteStop(); /0B07B
} W~XV
4kW30Ma
D..{|29,:
System.err.println("文件下载结束！"); c,#~L7
} J~_L4*Jw
catch(Exception e){e.printStackTrace ();} }m=tzHB*
} p56KS5duI.
)bB"12Z|8
g|&.v2 '
//获得文件长度 J8sJ~FnUj
public long getFileSize() l _kg3e4
{ u4b3bH9U
int nFileLength = -1; LY@1@O2@
try{ hj^G}4
URL url = new URL(siteInfoBean.getSSiteURL()); E5,%J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s)=!2AY
httpConnection.setRequestProperty("User-Agent","NetFox"); -Z`(? k
6=Y3(#Ddt
c]AKeq]
int responseCode=httpConnection.getResponseCode(); mhHA!:Y
if(responseCode>=400) 8! |.H p
{ EmtDrx4!(f
processErrorCode(responseCode); U~u6}s]:
return -2; //-2 represent access is error >:Rt>po8|w
} z")3_5Br
p0}+071o%
{#dp-5V
String sHeader; 8k+q7
u%+6Mp[E
jQ.>2-;H9
for(int i=1;;i++) !uj!
{ 8!`7-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'Yaf\Hp
//Utility.log(in.readLine()); B#qL$M,|
sHeader=httpConnection.getHeaderFieldKey(i); [M7iJcwt
if(sHeader!=null) |0C|$2
{ Z`-)1!
if(sHeader.equals("Content-Length")) ({d,oU$>y
{ dvg;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x*loACee.
break; "W?l R4
} x*,q Rew
} Hm+6QgCs
else }<5\O*kX4
break; b:}wR*Adc
} bik] JIM
} dUsJv
catch(IOException e){e.printStackTrace ();} "xvV'&lQ
catch(Exception e){e.printStackTrace ();} sUyCAKebRr
2-"Lxe65f
z) ]BV=
Utility.log(nFileLength); |!4BWt
s]nGpA[!
z{D$~ ob
return nFileLength; G:h;C].
} 2g ?Jb5)
)E[ Q
?;ALF
//保存下载信息（文件指针位置） 2HvTM8
private void write_nPos() +H)!uLvaB
{ V',m $
try{ :w {M6mM>
output = new DataOutputStream(new FileOutputStream(tmpFile)); #GDh/t2@
output.writeInt(nStartPos.length); /H\^l.|vk
for(int i=0;i<nStartPos.length;i++) 8^P2GG'+-
{ 323yAF
// output.writeLong(nPos); *hk{q/*Qw
output.writeLong(fileSplitterFetch.nStartPos); k2_6<v Z
output.writeLong(fileSplitterFetch.nEndPos); MQ9M%>
} ,z0~mN
output.close(); vjs|!O=oH
} gNEzlx8A
catch(IOException e){e.printStackTrace ();} H649J)v+m
catch(Exception e){e.printStackTrace ();} evndw>
} ^huBqEs
^V XXq
n7`.<*:
//读取保存的下载信息（文件指针位置） Sq?6R}q%
private void read_nPos() eSvc/CU
{ ;4S [ba1/
try{ ?v)"%.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $X.'W\o|
int nCount = input.readInt(); hIzPy3
nStartPos = new long[nCount]; %~B)~|h
nEndPos = new long[nCount]; \0*yxSg,^
for(int i=0;i<nStartPos.length;i++) QRg"/62WCD
{ /\3XARt
nStartPos = input.readLong(); `F-Dd4B
nEndPos = input.readLong(); *FLTz(T
} T,xVQ4J?
input.close(); fr,CH{Uq
} VxPTh\O*[
catch(IOException e){e.printStackTrace ();} Y00i{/a 8
catch(Exception e){e.printStackTrace ();} bAy5/G!_R
} ?VOs:sln
nI|Lx`*v
HkfSx rTgQ
private void processErrorCode(int nErrorCode) c~0VNuN
{ eHnei F
System.err.println("Error Code : " + nErrorCode); "u,~yxYWl
} 5EV8zf
qs8K jG@
3*2&Fw!B
//停止文件下载 {Gb)Et]<
public void siteStop() gk_Xu
{ &>) `P[x
bStop = true; A\PV@w%Ai
for(int i=0;i<nStartPos.length;i++) .f.j >
fileSplitterFetch.splitterStop(); sxC{\iLY%
S{"6PXzb
g*w-"%"O
} -%/,j)VKD
} <-oRhi4
//负责部分文件的抓取 (W}i287
**FileSplitterFetch.java HZr/0I?
*/ =DF@kR[CH"
package NetFox; 1+i
*2m&?,nJ
t#D\*:Xi
import java.io.*; 7zP
import java.net.*; /xrq'|r?C
/J9T=N
c J"]yG)=
public class FileSplitterFetch extends Thread { d,Dg"Z
Z#cU#)`y1
;ijfI
String sURL; //File URL \ \mO+N47i
long nStartPos; //File Snippet Start Position \'^Z_6{w
long nEndPos; //File Snippet End Position Med"dHo7
int nThreadID; //Thread's ID n nnA,
boolean bDownOver = false; //Downing is over *V@MAt
boolean bStop = false; //Stop identical g9lg
FileAccessI fileAccessI = null; //File Access interface E*T84Jh6
T=f;n;/>
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2G:{FY
{ @SQ*/sw (c
this.sURL = sURL; Fp|rMq
this.nStartPos = nStart; W*/s4 N
this.nEndPos = nEnd; n`I jG
nThreadID = id; nO.+&kA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -5-SlQu
} 3_1Io+uXk
3xCA\*
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public void run() %ucmJ-<y#
{ 23n8,} H,
while(nStartPos < nEndPos && !bStop) * SON>BSF
{ Kp=3\)&
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vM4`u5
try{ fdH'z:Xao
URL url = new URL(sURL); v8fZ?dx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pt|$bU7
httpConnection.setRequestProperty("User-Agent","NetFox"); ;Q,).@<C
String sProperty = "bytes="+nStartPos+"-"; |s3HeY+Co
httpConnection.setRequestProperty("RANGE",sProperty); PA-0FlV|
Utility.log(sProperty); g7Q*KA+
*ej o6>
,E8>:-boL
InputStream input = httpConnection.getInputStream(); `_{'?II
//logResponseHead(httpConnection); 3L!&~'.Ro
nTtt$I@hW
yNMwd.r[
byte[] b = new byte[1024]; vheAh`u^&
int nRead; OFAqP1o{$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {j=hQL3
{ R^O)fL0_
nStartPos += fileAccessI.write(b,0,nRead); LAVt/TcZS|
//if(nThreadID == 1) ;eEtdoy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N4]6LA6x6
} [N$_@[
jvKaxB;e
#&8pp8wd,}
Utility.log("Thread " + nThreadID + " is over!"); ,HO/Q6;N
bDownOver = true; 0v)mgrl=,
//nPos = fileAccessI.write (b,0,nRead); {8p?we3l1
} PH4bM
catch(Exception e){e.printStackTrace ();} Qs[EA_
} IEsD=
} FEi,^V
Pg8=
Pc ?G^ Xol
//打印回应的头信息 v5bb|o[{K
public void logResponseHead(HttpURLConnection con) Hf]}OvT>Z
{ cz~11j#
for(int i=1;;i++) L$?~TY
{ "=TTsxyM6P
String header=con.getHeaderFieldKey(i); WoG
if(header!=null) 5Fm?,^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (2(;u1
Utility.log(header+" : "+con.getHeaderField(header)); `e;Sjf<
else .0;k|&eBD
break; f2e$BA
} &MLhCekY
} |BWK"G
WG=r? xE
?B:wV?-`
public void splitterStop() <;Z~ vZ]
{ -ns a3P
bStop = true; X_S]8Aa
} F7u%oLjr
(=B7_jrl
5*'N Q010
} 6 FxndR;
KFG^vmrn
e7AI&5Eg{
/* JV{!Ukuyp+
**FileAccess.java t7%Bv+Uo
*//文件访问(定位，写) c)~|#v
package NetFox; X \ZUt >
import java.io.*; _^$b$4)
%ycT}Lu
\V\ET
public class FileAccessI implements Serializable{ |}Z"|-Z
QN5N hs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AQGE(%X
RandomAccessFile oSavedFile; 5fv6RQD
long nPos; =umS^fJ5`
2*E<G|-F
A^7Zy79
public FileAccessI() throws IOException Ev ,8?
{ Ekp 0.c8:
this("",0); 4nXS9RiF2
} :iiTz$yk
bvvx(?!
:WTvP$R
public FileAccessI(String sName,long nPos) throws IOException !H.lVA
{ Rzj!~`&N
oSavedFile = new RandomAccessFile(sName,"rw"); I=I%e3GEm
this.nPos = nPos; @D{[Hj`<
oSavedFile.seek(nPos); r/:'}os;
} oK[,xqyA
Y0'^S<ox
gvt4'kp
public synchronized int write(byte[] b,int nStart,int nLen) }+3~y'k
{ @&> +`kgU-
int n = -1; Ki\jiflc7
try{ (~o+pp!
oSavedFile.write(b,nStart,nLen); 'm((G4
n = nLen; *Y?]="8c#;
} ]c+'SJQ
catch(IOException e) >u[ln@ l
{ </Lqk3S-!
e.printStackTrace (); hZG{"O!2s
} P3>2=qK"E(
8\_,Y ji
^<b.j.$<z
return n; 0+h?Bk
} %uMsXa
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Y^f|}YO%y
} K|!)<6ZsG7
P1jkoJ
V!!'S h
/* _Y~?.hs^
**SiteInfoBean.java v:b%G?o
*/ |9JYg7<
package NetFox; I<#kw)W!
94/}@<d-=
o4795r,jz
public class SiteInfoBean { Yq.@7cJ
,^T2hY`
]kvE+m&p}^
private String sSiteURL; //Site's URL '93&?
private String sFilePath; //Saved File's Path c" HCc]
private String sFileName; //Saved File's Name fTcRqov
private int nSplitter; //Count of Splited Downloading File @UBp;pb}=h
>X,6
:eO0{JN4T
public SiteInfoBean() v<**GW]neD
{//nSplitter的缺省值为5 ea/6$f9^
//default value of nSplitter is 5 JJa?"82FXZ
this("","","",5); }%|OnEk"
} uEY5&wX`
{^iV<>J
W3kilhZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a WC sLH
{ >n62csO
sSiteURL= sURL; kE}Ib4]J
sFilePath = sPath; Kxn=iv^Ir
sFileName = sName; !Ai;S
this.nSplitter = nSpiltter; yuq E
0&@6NW&Mu
g;1 UZE;
} vF1$$7k
,$>Z= ~x*
U/X ^
public String getSSiteURL() s,8%;\!C
{ !LA#c'
return sSiteURL; ]a()siT
} #t*c*o
7tQiKrhp
K(Nk|gQ
public void setSSiteURL(String value) &/" qOZAs
{ Ar_/9@n
sSiteURL = value; 5irOK9hK
} ah.Kb(d:
`Hqu2 '`
%|~UNP$
public String getSFilePath() Y,r2m nq
{ SQ[}]Tm;n
return sFilePath; .j },
} hB4.tMgZ
bBf+z7iyc
|m%&Qb
public void setSFilePath(String value) g}7B0 yo
{ O_q_O
sFilePath = value; s&l[GKR
} /WMLr5
Phczf
f.{0P-Np
public String getSFileName() ( KrIMZ
{ ~kga+H
return sFileName; f\JyN@w+
} hV%l}6yS&
}\F>z
)_ y{^kn3^
public void setSFileName(String value) VI4d/2e
{ :>5]A6Wi
sFileName = value; OkM>
} -llujB%;,e
~Hq 2'
l#Tm`br
public int getNSplitter() r]yq #T`z
{ ,^(T^ -
return nSplitter; Hcpw[%(
} K|&y?w
TFhj]r^{
UTz;Sw?~hw
public void setNSplitter(int nCount) DRnXo-Aaj
{ -p1arA
nSplitter = nCount; Co M8
} l40$}!!<
} %2{E'^#)p-
GZ%RfKyQ
ETIf x)B-
/* X$aMf&x
**Utility.java z"-Urd^O
*/ <5.{+!BM
package NetFox; ` mi!"pmw
m-:k]9I
Oj2[(7mO/
public class Utility { (8{Z@
(]JJ?aAF
%+.]>''a
public Utility() S'WmPv
{ _MR2,mC
$]vR,E
{>:2Ff]O:
} cIX59y#7
`U1"WcN
//线程睡眠 3ySnAAG
public static void sleep(int nSecond) 3+Q6<MS q
{ IRQ(/:]
try{ X!@Gv:TD
Thread.sleep(nSecond); c}Qc2D3*
} ?E`J-ncP
catch(Exception e) Djzb#M'm
{ o)$sZ{` ="
e.printStackTrace (); 67e1Y@Xu
} ]KfHuYjM
} ,Ya&M@^Z
0YS*=J"7z
//日志 q*T+8O
public static void log(String sMsg) cc>h=%s`
{ -{O2Nv-]]
System.err.println(sMsg); 6Hz=VhQrN
} f7`y*9^
sU8D;ML7
\nLO.,
public static void log(int sMsg) k_skn3,u
{ A4#m&o
System.err.println(sMsg); {>i'Pb0mG|
} ScI9.{
} rnW i<Se
DCNuvrZ
ZK;HW
/* XhS<GF%
**TestMethod.java OTRTa{TB
*/ 8z+ CYeV
package NetFox; +"C0de|-
F2u{Wzr_@
bZ389dSn
public class TestMethod { kqyY:J
Jlzhn#5c-
}/=VnCfU
public TestMethod() NZl0sX.:
{ ///xx/weblogic60b2_win.exe q3;HfZ
try{ V7&L+]!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |OC6yN *P)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); al5?w{us
SiteFileFetch fileFetch = new SiteFileFetch(bean); v(afaN
fileFetch.start(); Fv3fad@x
} #R)$nv:h?^
catch(Exception e){e.printStackTrace ();} !6kLg1
8\[6z0+;
LOQEU?z
} m\Dbb.vBvW
# wG}T .*
E)`+1j
public static void main(String[] args) FuD$jsEw
{ kweypIB
new TestMethod(); {RzlmDStV
} <$UY{"?
} O|8p #
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