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)); F <.} q|b
} vW03nt86
for(int i=0;i<nEndPos.length-1;i++) .KxE>lJbqM
{ ?sbM=oo
nEndPos = nStartPos[i+1]; KDYyLkI dr
} fqZ+CzH
nEndPos[nEndPos.length-1] = nFileLength; C/!8NV1:4
} (^= Hq'D
} (=w ff5U
0@2pw2{Ru
hJ0m;j&4y
//启动子线程 Yd$64d7,h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N0&#fXO
for(int i=0;i<nStartPos.length;i++) K9Bi2/N
{ 5h>t4 [~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /[Sy;wn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vQL)I
nStartPos,nEndPos,i); #mbl4a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !' jXN82
fileSplitterFetch.start(); ybVdWOqv
} $:<G=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bn8?-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `L?9-)m<f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (1}"I RX.
nEndPos = " + nFileLength); 6T=zHFf~
// fileSplitterFetch[nPos.length-1].start(); {y7,n
!GBGC|avE
b6gD*w<
//等待子线程结束 Mta;6<
//int count = 0; ]@7]mu:oL
//是否结束while循环 eZ +uW0
boolean breakWhile = false; \ /6m
Ia>>b #h
b}jLI_R{
while(!bStop) U-GV^j
{ ^1NtvQe@Y\
write_nPos(); |cq%eN
Utility.sleep(500); AZadNuL/
breakWhile = true; T#w *5Qf
s*W)BK|+?
]<\; -i)
for(int i=0;i<nStartPos.length;i++) 7`6JK
{ IXmO1*o@
if(!fileSplitterFetch.bDownOver) ti9cfv>
{ !YEU<9
breakWhile = false; G/C5o=cY
break; g@7j<UY
} =Pgu?WU@
} 1">]w2je:
if(breakWhile) m1lfC
break; "6%vVi6
4C_-MJI
5s2334G
//count++; bNO/CD4
//if(count>4) D^H<)5d9
// siteStop(); 1MzOHE
} Rd.[8#7VE
G0eJ<*|_ 3
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System.err.println("文件下载结束！"); s%~p?_P
} MF^I] 7_
catch(Exception e){e.printStackTrace ();} ()+;KF8
} 5-pz/%,
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n"{oj7E0a
//获得文件长度 v]HiG_C
public long getFileSize() U%na^Wu
{ -/#tQ~{gs
int nFileLength = -1; <ArP_! `3
try{ C&ivjFf
URL url = new URL(siteInfoBean.getSSiteURL()); v`$9;9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WtTwY8HC
httpConnection.setRequestProperty("User-Agent","NetFox"); X*'-^WM6
~ ]q^Akq
W[3)B(Vq<E
int responseCode=httpConnection.getResponseCode(); kM\O2ay
if(responseCode>=400) <ST#< $%
{ k&P_ c
processErrorCode(responseCode); GX lFS#`
return -2; //-2 represent access is error fE/8;v!=
} -j_J1P0,
:B'}#;8_
:{tvAdMl7
String sHeader; l<$c.GgFd
V ;)q?ZHg
-W+67@(\8H
for(int i=1;;i++) w{"GA~=
{ a4}2^K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p=(;WnsK
//Utility.log(in.readLine()); M_4g%uHG
sHeader=httpConnection.getHeaderFieldKey(i); PaFJw5f
if(sHeader!=null) W+~ w
{ .SdEhW15)
if(sHeader.equals("Content-Length")) wQ,RZO3
{ "ppT<8Qi'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VPTT*a`
break; RfB""b8]=
} =#<hT s
} ?s5zTT0U>$
else y6o^ Knl
break; sy`:wp
} (r.{v@h,dV
} v;;X2 a1k
catch(IOException e){e.printStackTrace ();} puv*p%E
catch(Exception e){e.printStackTrace ();} ^F~e?^s
szwXr
K`FgU7g{
Utility.log(nFileLength); Tc)T0dRP
%f&(U/
~&~%qu
return nFileLength; .so{ RI
} l1N{ujM
;NRT a*
= sIR[V'(
//保存下载信息（文件指针位置） 9hT^Y,c0
private void write_nPos() y+?tUSPP
{ IR%a+;Xs
try{ 9kP!O_
output = new DataOutputStream(new FileOutputStream(tmpFile)); vmOXB#7W
output.writeInt(nStartPos.length); 9VN@M
for(int i=0;i<nStartPos.length;i++) <E BgHD)
{ +c\s%Gzrh
// output.writeLong(nPos); vd /_`l.D
output.writeLong(fileSplitterFetch.nStartPos); KW&&AuPb}
output.writeLong(fileSplitterFetch.nEndPos); r[Q$w>
} n a2"Sy=Yi
output.close(); &bj :,$@
} =tH+e7it
catch(IOException e){e.printStackTrace ();} [ylGNuy
catch(Exception e){e.printStackTrace ();} VSZ6;&2^
} im+2)9f
_'H<zZo
u?g!E."v
//读取保存的下载信息（文件指针位置） H8K<.RY
private void read_nPos() P+3G*M=}
{ ".xai.trr
try{ s80_e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /@RnCjc'
int nCount = input.readInt(); uU.9*B=H9
nStartPos = new long[nCount]; #K!Df%,<
nEndPos = new long[nCount]; pLzsL>6h
for(int i=0;i<nStartPos.length;i++) &,."=G
{ ?GFxJ6!%I
nStartPos = input.readLong(); ].dTEzL9X
nEndPos = input.readLong(); y=vH8D]%X
} 9'toj%XQ
input.close(); Hs=!.tZ,
} {|xwvTlJ
catch(IOException e){e.printStackTrace ();} qW7"qw=
catch(Exception e){e.printStackTrace ();} A]U]
} ;$&-c/]F#
sD{b0mZT
L''0`a. +S
private void processErrorCode(int nErrorCode) `6mHt6"h
{ fe37T@
System.err.println("Error Code : " + nErrorCode); "}SERC7
} Lf0Hz")
y-n\;d>[(
}aNiO85
//停止文件下载 }7=a,1T
public void siteStop() DhZtiqL#_
{ Xq>e]#gR
bStop = true; -;P<Q`{I
for(int i=0;i<nStartPos.length;i++) kw-/h+lG
fileSplitterFetch.splitterStop(); Rc6 )v
b7AuKY{L
uaPBM<
} Msd!4TrBJ
} Km <Wh=
//负责部分文件的抓取 X^|oY]D
**FileSplitterFetch.java zK-hNDFL{
*/ \aZ(@eF@@Q
package NetFox; 0='DDy
Ab2g),;c
CY>NU
import java.io.*; l(]\[}.5
import java.net.*; 5&X
ZHC sv]l
[QZ~~(R
public class FileSplitterFetch extends Thread { 2/7=@>|
%o"Rcw|
[BQw$8+n_
String sURL; //File URL gs8L/veP
long nStartPos; //File Snippet Start Position K%pmE?%,8
long nEndPos; //File Snippet End Position #dpt=
int nThreadID; //Thread's ID q5vs;,_ |
boolean bDownOver = false; //Downing is over /2@%:b)
boolean bStop = false; //Stop identical >|Jw,,uf
FileAccessI fileAccessI = null; //File Access interface 4|$D.`Wu
D} .t
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException phc1AN=[E
{ f0D Ch]
this.sURL = sURL; $k`8Zx w
this.nStartPos = nStart; @^` <iTK&p
this.nEndPos = nEnd; 4*+EUJ|
nThreadID = id; 7@lXN8_f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]F@md(J
} }a9C/t3
Nr[Rp
\OU+Kl<
public void run() li%-9Jd
{ &16bZw
while(nStartPos < nEndPos && !bStop) M)J*Df0@
{ ^X&9"x)4
\W}EyA
lTB!yF.r|
try{ Pj.~|5gnf
URL url = new URL(sURL); ,#E5/'c`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oba*w;
httpConnection.setRequestProperty("User-Agent","NetFox"); jO,<7FPs5
String sProperty = "bytes="+nStartPos+"-"; =wj~6:Bf
httpConnection.setRequestProperty("RANGE",sProperty); WD\{Sdx:r
Utility.log(sProperty); 0wkLM-lN
llleo8
k_a'a)`$6
InputStream input = httpConnection.getInputStream(); t<|s&
//logResponseHead(httpConnection); .u*].As=
t~M<j|]k
y[|g!9Rp
byte[] b = new byte[1024]; =+"'=o
int nRead; <=inogf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o 4b{>x
{ DrEtnt
nStartPos += fileAccessI.write(b,0,nRead); tbPPI)lu
//if(nThreadID == 1) p&4n3%(R@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >o} ati
} s =5H.q%PV
q],R6GcVr
P\s+2/
Utility.log("Thread " + nThreadID + " is over!"); jkP70Is
bDownOver = true; KNg5Ptk
//nPos = fileAccessI.write (b,0,nRead); 5qr!OEF2
} 1ZL_;k
catch(Exception e){e.printStackTrace ();} fv_wK_. %:
} GiZ'IDV
} !p&'so^-W
SNU bY6
AY;+Ws
//打印回应的头信息 v 2GhR*
public void logResponseHead(HttpURLConnection con) ^<VE5OM
{ z`5I1#PVA
for(int i=1;;i++) Ozv.;}SE
{ vs@:L)GW\
String header=con.getHeaderFieldKey(i); 7:L~n(QpP
if(header!=null) 668bJ.M\O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U(N$6{i_
Utility.log(header+" : "+con.getHeaderField(header)); M([H\^\:
else \!QF9dP4
break; =Yj[MVn
} lkZC?--H
} 5 WppV3;
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_;q-+"6L;
public void splitterStop() `fkrik
{ %'T>kz*A
bStop = true; 2jZ}VCzRG
} 48g^~{T4O
JYr7;n'!
}AiS83B
} YhT1P fl
nh=Us^xD
arLl8G[
/* (<C%5xk
**FileAccess.java 6h_k`z
*//文件访问(定位，写) |<|,RI?
package NetFox; V3W85_*
import java.io.*; NydW9r:T
YB{E=\~
mY8=qkZE
public class FileAccessI implements Serializable{ >ij4z N
/V<`L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rgzI
RandomAccessFile oSavedFile; dO4#BDn"=
long nPos; ]0i2]=J&,
pmyM&'#Id
Au._n,<
public FileAccessI() throws IOException +@uC:3jM
{ ^Ai_/!"
this("",0); .r|vz6tU?
} &E &iaw!
\ui^ d
4D8yb|o
public FileAccessI(String sName,long nPos) throws IOException I!7.fuO
{ W:poUG1UR
oSavedFile = new RandomAccessFile(sName,"rw"); /e sk
this.nPos = nPos; m=.7f9
oSavedFile.seek(nPos); OEE{JVeI
} y}-S~Ov>I
.(1j!B4^
0^&R7Rv c
public synchronized int write(byte[] b,int nStart,int nLen) xnQGCw?S&}
{ O4PdN?
int n = -1; :_\!t45
try{ E9d i
oSavedFile.write(b,nStart,nLen); quGPk)c
n = nLen; 01c/;B
} i5<Va@ru!s
catch(IOException e) Wx|6A#cg!
{ <oaBh)=7
e.printStackTrace (); } o"_#\6
} .02(O
HjK<)q8b
?*R^?[
return n; ?3TK7]1V:
} (bFWT_CChz
KO]?>>5S6
l6B^sc*@
} gqdB!l4
KaQq[a
:y-0qzD?
/* mERZ_[a2
**SiteInfoBean.java _ K+V?-=
*/ A[ECa{v
package NetFox; 2V2x,!
UE,~_hp
%cr]ZR
public class SiteInfoBean { PDq}Tq
8P<UO
9MtJo.A
private String sSiteURL; //Site's URL Ul713Bjz
private String sFilePath; //Saved File's Path {8Jk=)(md
private String sFileName; //Saved File's Name <#p|z`N
private int nSplitter; //Count of Splited Downloading File h[|zs>p
dI ZTLb"a
C3b0`|5
public SiteInfoBean() mf]( 3ZL
{//nSplitter的缺省值为5 E2h;hr;W
//default value of nSplitter is 5 WQLHjGehe
this("","","",5); t2-nCRXEP
} }M9DqZ;I
Nzi/3r7m
R3{*v =ov
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [mB(GL
{ rxgVT4
sSiteURL= sURL; tY$ty0y-e
sFilePath = sPath; X|1_0
sFileName = sName; Xk&F4BJQk<
this.nSplitter = nSpiltter; /romTK4
"'}v0*[
f0mH|tI`
} +ptF-
;+ Co!L
IQlw 914
public String getSSiteURL() 3dxnh,]&@
{ yrE,,N%I
return sSiteURL; F'UguC">
} Dmm r]~
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CVGOX z
public void setSSiteURL(String value) bco[L@6G$
{ y800(z
sSiteURL = value; nT@6g|!
} orQV'
17n+4J]
6N%L8Q
public String getSFilePath() SZK)q
{ 4gv.E 0Fo
return sFilePath; yYG3/Z3u5
} A1|7(Sow
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public void setSFilePath(String value) vNK`Y|u@
{ ezg^5o;
sFilePath = value; p'Y&Z?8
} '?`@7Eol
u1pc5 Y{
\=EY@*=
public String getSFileName() [DotS\p!z
{ u>t|X}JH
return sFileName; @`IXu$Wm(
} '!+P{
gI^L 9jE7
^EC)~HP@C
public void setSFileName(String value) M}=s3[d(,
{ }rKJeOo^x?
sFileName = value; ,#P,B;r~
} &Hlm{FHU
k%Ma4_Z
<m Ju v
public int getNSplitter() +3/k/W
{ *w'q
return nSplitter; Q3NPwM
} DnG/ n
&O+sK4P
f!M[awj%
public void setNSplitter(int nCount) h V|v6 _
{ Z^'?|qFj!
nSplitter = nCount; &J lpA<^s;
} J8GXI:y
} P7'oXtW{o
KrdZEi vb
}@rg5$W
/* QD.zU/F~>
**Utility.java dN]Zs9]
*/ inr%XS/m
package NetFox; 2YE;m&
4T-,'P{?
KMxNH,5
public class Utility { 6?3/Ul}
J{Y6fHFi
IgPV#
public Utility() ^eTDD
{ T:K"
#D|! .I)
Z/89&Uy`h
} lj "Z
>\|kJ?h
//线程睡眠 YVQ_tCC_!
public static void sleep(int nSecond) la G$v-r
{ YBYBOH
try{ a)3O? Y
Thread.sleep(nSecond); Vl5SL{+D
} ZNzR`6}
catch(Exception e) _'!aj+{
{ &\;<t,3A~
e.printStackTrace (); u @{E{
} pY+.SuM
} 7ei>L]gm%
L.C ^E7;Z_
//日志 zY7*[!c2
public static void log(String sMsg) (v|r'B9b
{ BA~a?"HS
System.err.println(sMsg); T"L0Iy!k;
} Ys"|</;dbj
.dD9&n;#^
B<|:K\MA
public static void log(int sMsg) .ocx(_3G
{ Zu\p;!e
System.err.println(sMsg); 2Pbe~[
} Q)x?B]b-
} w{k1Y+1
RL?u n}Qa
u] F70C^~
/* :7 qqjs
**TestMethod.java Jt##rVN
*/ zq,iLoY[R
package NetFox; ayV6m
>;&Gz-lm
|HrM_h<X
public class TestMethod { ;EgzC^2e
`^v4zWDK
S304ncS|M
public TestMethod() u9TzZ
{ ///xx/weblogic60b2_win.exe G 6Wx3~
try{ ( MB`hk-d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M (+.$uz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l%rx#;=u
SiteFileFetch fileFetch = new SiteFileFetch(bean); cqeR<len
fileFetch.start(); /SnynZ.q
} :|Z$3q
catch(Exception e){e.printStackTrace ();} R;H?gE^m-
1a<]$tZk
J__;.rnk
} ykxbX
q^Z~IZ8IT
+p13xc?#j
public static void main(String[] args) -G8c5b[
{ VBu8}}Ql
new TestMethod(); z)5S^{(
} 'dkXYtKCB
} #2h+dk$1
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