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)); 4`Nt{
} -IlJ^Al4
for(int i=0;i<nEndPos.length-1;i++) 8,O33qwH
{ Gc.P,K/hr
nEndPos = nStartPos[i+1]; 2nb:)
} ;o/>JHGj
nEndPos[nEndPos.length-1] = nFileLength; Hv]7e|
} "M|P+A
} #U=X NU}k
;v17K
wdzOFDA
//启动子线程 .yT8NTu~0j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mD:IO
for(int i=0;i<nStartPos.length;i++) z3t~}aL
{ 4>^K:/y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?Y:x[pOe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;)Kh;;e
nStartPos,nEndPos,i); Vh3Ijn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H9 C9P17
fileSplitterFetch.start(); Y\],2[liF
} y5= `ap
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ae^X35
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p <eC<dtu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @ZN^1?][
nEndPos = " + nFileLength); 3$vRW.c\q
// fileSplitterFetch[nPos.length-1].start(); Md)zEj`\
!KKT[28v
k^$+n_
//等待子线程结束 J68j=`Y
//int count = 0; o01kYBD
//是否结束while循环 Mcw4!{l`
boolean breakWhile = false; sDgXU@
WqxUXH
*BD=O@
while(!bStop) lcON+j
{ *5sBhx
write_nPos(); ?^' 7+8C*J
Utility.sleep(500); UE _fpq
breakWhile = true; _u"nvgVz9
2LCB])X
M)?dEgU}M
for(int i=0;i<nStartPos.length;i++) lX:|iB
{ OE)~yKy
if(!fileSplitterFetch.bDownOver) ?EMK8;
{ X.ONa_
breakWhile = false; 2c<&eX8"
break; NT%W;)6m9
} :J}t&t
} M-NV_W&M
if(breakWhile) <1w/hy&mWN
break; h:XzUxL\
8,?v?uE
-3Avs9`5
//count++; H-rWDN#
//if(count>4) /Y[~-Y+!,
// siteStop(); PIA)d-Z
} 4vK8kkW1
s/"&9F3
Zn:R PMk*
System.err.println("文件下载结束！"); BE&B}LfvfO
} Xqp|VbDca
catch(Exception e){e.printStackTrace ();} *fO3]+)d+
} 8T;IZ(s
VS#wl|b8
6Dws,_UAZ4
//获得文件长度 0YH+B
public long getFileSize() tC8(XMVx
{ C8@TZ[w
int nFileLength = -1; u{&B^s)k.
try{ =9L$L|W
URL url = new URL(siteInfoBean.getSSiteURL()); {-9jm%N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iK;dU2h
httpConnection.setRequestProperty("User-Agent","NetFox"); +&tgJ07A
4!$ M q;U
-7WW[ w
int responseCode=httpConnection.getResponseCode(); HQ!Xj.y
if(responseCode>=400) puSLqouTM
{ C2]Kc{4
processErrorCode(responseCode); B;Nl~Y|\
return -2; //-2 represent access is error SEQ%'E5-'
} T1B|w"In
ZWc+),X
JGiKBm;
String sHeader; #Z=tJ
||2Q~*:
hf!|\f
for(int i=1;;i++) F}Mhs17!|
{ Jsg I'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;S$Ll*f>D
//Utility.log(in.readLine()); 5yh/0i5|
sHeader=httpConnection.getHeaderFieldKey(i); JnD{J`:
if(sHeader!=null) &a> lWE
{ y$Zj?Dd#
if(sHeader.equals("Content-Length")) >1L=,M
{ t^=U*~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); mIZwAKo
break; O|kKwadC
} JL}\*
} u#W5`sl
else ?<X(]I.j
break; TL= YQA
} NW$H"}+o
} CozKyt/r7
catch(IOException e){e.printStackTrace ();} P#kGX(G9!
catch(Exception e){e.printStackTrace ();} D|I Ec?
:(3|HTz
NX* O_/
Utility.log(nFileLength); (J$\-a7<f
z^* '@
kg5ev8
return nFileLength; RR1A65B
} J}spiVM
v=YK8fNi
Pvo#pY^dXX
//保存下载信息（文件指针位置） bTmL5}n
private void write_nPos() #$S}3 o
{ ;:&?=d
try{ VBoMT:#
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~ <0Z>qr
output.writeInt(nStartPos.length); :L?_Y/K
for(int i=0;i<nStartPos.length;i++) `Y?t@dd
{ hVoNw6fE
// output.writeLong(nPos); $KV&\Q3\0
output.writeLong(fileSplitterFetch.nStartPos); PsjbR
output.writeLong(fileSplitterFetch.nEndPos); ]*"s\ix
} XY7Qa!>7j
output.close(); a+41|)pt
} /%x7+Rl\-^
catch(IOException e){e.printStackTrace ();} !&kL9A).
catch(Exception e){e.printStackTrace ();} +,'T=Ic{
} zbw7U'jk
`cP <}^]
.;/L2Jv
//读取保存的下载信息（文件指针位置） S^RUw
private void read_nPos() qG8s;_G
{ qX:B4,|ck
try{ ,1n >U?5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vvu<:16
int nCount = input.readInt(); S[M4ukYK
nStartPos = new long[nCount]; A(6xg)_XQ
nEndPos = new long[nCount]; -H(vL=
for(int i=0;i<nStartPos.length;i++) BWPP5X9
{ Gu(lI ~
nStartPos = input.readLong(); .,2V5D-${
nEndPos = input.readLong(); HP2wtN{Zs
} rp! LP#*
input.close(); E,G<_40
} =y ]Jl,_.
catch(IOException e){e.printStackTrace ();} i`U:gw
catch(Exception e){e.printStackTrace ();} a^nAZ
} uq7T{7~<
8 ,}ikOZ?
0O@_cW
private void processErrorCode(int nErrorCode) y+mElG$F
{ kka"C]!
System.err.println("Error Code : " + nErrorCode); 7 &)]) {Q
} vL_zvXA
=fLL|
#mc!Wt10
//停止文件下载 H>7dND2;
public void siteStop() ~2}Pl)
{ 3*S[eqMJc
bStop = true; Ng<1Sd|MV
for(int i=0;i<nStartPos.length;i++) ~&G4)AM
fileSplitterFetch.splitterStop(); g#^|oYuH6
9V!-ZG
N{akg90
} HQVh+(
} 7Ur?ep
//负责部分文件的抓取 WnxEu3U
**FileSplitterFetch.java '8Wv.X0`
*/ _."E%|5
package NetFox; I=dGq;Jaz
?qHF}k|
e$l6gY
import java.io.*; V% axeqs
import java.net.*; 4KpL>'Q=
^[# & ^[-V
WO</Q6+
public class FileSplitterFetch extends Thread { DQ6jT@ZDH
a0_(eO-S
83;IyvbL
String sURL; //File URL ?T*";_o,B
long nStartPos; //File Snippet Start Position XF,<i1ZlM
long nEndPos; //File Snippet End Position )q^ Bj$
int nThreadID; //Thread's ID m@qqVRn#)
boolean bDownOver = false; //Downing is over ;b~~s.+
boolean bStop = false; //Stop identical B!,yfTk]
FileAccessI fileAccessI = null; //File Access interface L/r{xS
R9dP,<2
?X_V#8JK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U{1z;lJ
{ \ElX~$fS
this.sURL = sURL; 1M5 -pZ[D
this.nStartPos = nStart; Y(i?M~3\t
this.nEndPos = nEnd; /A(NuB<Pq
nThreadID = id; hw,^G5m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >]$aoA#
} }C6@c1myq-
X-Ycz 5?
ey1Z/|
public void run() 5{l1A(b
{ %`\]Y']R
while(nStartPos < nEndPos && !bStop) 9U<Hf32
{ &TT":FPR
V/y=6wUiSl
1kFjas`g
try{ R_e)mkE
URL url = new URL(sURL); M []OHw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jMU9{Si
httpConnection.setRequestProperty("User-Agent","NetFox"); }B)jq`a?|\
String sProperty = "bytes="+nStartPos+"-"; Vewzo1G2
httpConnection.setRequestProperty("RANGE",sProperty); y4F^|kS) [
Utility.log(sProperty); ,b'4CF
aWvd`qA9r
f'{>AKi=C
InputStream input = httpConnection.getInputStream(); <MZi<Z`
//logResponseHead(httpConnection); 'U)8rR
4;<DJ.XlN=
h5onRa*7
byte[] b = new byte[1024]; pMN<p[MB
int nRead; ROoE%%8I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -<oZ)OfU
{ j[DIz@^
nStartPos += fileAccessI.write(b,0,nRead); a-PGW2G
//if(nThreadID == 1) g_ M-F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a!t V6H
} *T4ge|zUc
nFXAF!,jj
!<Z{@7oH
Utility.log("Thread " + nThreadID + " is over!"); <-)9>c:k
bDownOver = true; :kp0EiJ
//nPos = fileAccessI.write (b,0,nRead); T-P@u-DU
} =lrN'$z?%
catch(Exception e){e.printStackTrace ();} 8XbR
} X<xqT
} (!n-Age
E~He~wHWe
`pYE[y+
//打印回应的头信息 U42\.V0
public void logResponseHead(HttpURLConnection con) 1g i}H)
{ q<XcOc5
for(int i=1;;i++) 7Po/_%
{ E^syrEz
String header=con.getHeaderFieldKey(i); Ekf2NT
if(header!=null) v MWC(m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "k>bUe|RG
Utility.log(header+" : "+con.getHeaderField(header)); s^PmnFR
else `u=<c
break; h.b+r~u
} >B~?dTm
} s1=u{ET
nHU3%%%cU
y h-9u
public void splitterStop() >4'21,q
{ VRhRwdC
bStop = true; A_Gp&acs$
} =g2\CIlVU6
XI g|G}i.
4~WlP,,M
} jr1Se9u D
lt%-m@#/
yS"0/Rm}
/* '%O\E{h
**FileAccess.java J~2CD*v
*//文件访问(定位，写) m){&:Hs
package NetFox; j?J=w=.Nx
import java.io.*; ^K>pT}u
* D3
riEqW}{
public class FileAccessI implements Serializable{ ~[;{
fiqj;GW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^z?=?%{
RandomAccessFile oSavedFile; ]}_,U!`8
long nPos; "0Y&~q[=
L4mTs-M.
hGKdGu`0
public FileAccessI() throws IOException +}]wLM}\UF
{ 8)`5P\
this("",0); #ZwY?T x
} "2K|#,%N
V,'FlU
%>NRna
public FileAccessI(String sName,long nPos) throws IOException EM~7#Y
{ B2"+Hwbk
oSavedFile = new RandomAccessFile(sName,"rw"); )XZ,bz*jn
this.nPos = nPos; iy9VruT<x
oSavedFile.seek(nPos); ]=pWZ~A
} %w%zv2d
,,2_/u\"/i
"U{mMd!9L
public synchronized int write(byte[] b,int nStart,int nLen) qZc)Sa.S
{ gU*I;s>
int n = -1; >hesxC!
try{ CY\mU_.b
oSavedFile.write(b,nStart,nLen); vev8l\
n = nLen; ,XP@ pi
} !j'guT&9]
catch(IOException e) l?N`V2SuR
{ o}W7.7^2
e.printStackTrace (); -*5yY#fw}
} C890+(D~
3g+\?L-c
s-o~@(r6
return n; n7'<3t
} oPE.gn_$
\!6t
N}1-2
} yO%VzjJhg
n/:Z{
D`5: JR-{
/* +0)5H>h
**SiteInfoBean.java {S# 5g2
*/ ; vhnA$'a
package NetFox; ob)D{4B'
p@`4 Qz
|HT)/UZ|
public class SiteInfoBean { $jDD0<F.#
;vZ*,q6
l$qmn$Uc
private String sSiteURL; //Site's URL HKT{IP+7(L
private String sFilePath; //Saved File's Path K T"h74@
private String sFileName; //Saved File's Name ]*;RHy9
private int nSplitter; //Count of Splited Downloading File ~n)]dFy
gS0,')w
W>UjUq);
public SiteInfoBean() ">0 /8]l
{//nSplitter的缺省值为5 9 ?[4i'
//default value of nSplitter is 5 rUhWZta
this("","","",5); 047*gn.b
} (p'/p
+ 4++Z
d u_O}x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7Co3P@@
{ 6YB-}>?
sSiteURL= sURL; J#_\+G i
sFilePath = sPath; &7JEb]1C
sFileName = sName; vsxvHot=
this.nSplitter = nSpiltter; _y.mpX&
Ni/|C19Z
+lW+H12
} iOE9FW|e
U5T^S
sT@u3^>
public String getSSiteURL() #zh6=.,7
{ QLxXp
return sSiteURL; Ji)%Y5F
} 4"`=huQ
t>fA!K%{
})Ix.!p
public void setSSiteURL(String value) C8O7i[uc
{ "@F*$JGT y
sSiteURL = value; ;w>Q{z
} KI^q 5D ?
@*AYm-k
B`t)rBy
public String getSFilePath() 0EF,uRb
{ ~M|NzK_9
return sFilePath; `K@5_db\
} >c~9wv
-sruxF
_S[Rvb1e
public void setSFilePath(String value) x`b~ZSNJ%
{ `Nxo0Q
sFilePath = value; Ej9/_0lt
} %`8KG(F^
S S7D1
+Px<DX+
public String getSFileName() 7l4InR]
{ |~1rKzZwF
return sFileName; }Etd#">
} aH~x7N6!
+"*l2E]5
IDL^0:eg<.
public void setSFileName(String value) y'i:%n}I
{ bF8xQ<i~Y
sFileName = value; t(LlWd
} ;+#za?w
o%9Ua9|RR
;RTrRh0v
public int getNSplitter() !rN#PF>
{ TWD|1 di0
return nSplitter; ]y$V/Ij=qK
} !nqm ;96
C_g"omw40
rA>A=,
public void setNSplitter(int nCount) fS'k;r*r
{ )U3 H15
nSplitter = nCount; 5r2ctde)Y
} Z n"TG/:
} vi()1LS/!
$TH'"XK
519:yt
/* l%Fse&4\
**Utility.java D+@/x{wX2
*/ 7o 83|s.Bm
package NetFox; W6!4Qyn
U- UV<}
n+A'XBHk
public class Utility { !D|pbzQc8
d~xU?)n)
F"HI>t)>
public Utility() 0'`8HP
{ iMY0xf8l
'"G %0y
+h9l%Pz
} +X|m>9
Wvzzjcr(j
//线程睡眠 HK,G8:T
public static void sleep(int nSecond) ]R3pBC"Jv
{ v1tN DyM6
try{ &>wce5uV
Thread.sleep(nSecond); Jr*S2z<*
} U{:(j5m
catch(Exception e) ky lrf4=
{ ^|hRu{QW
e.printStackTrace (); z)?#UdBQv
} %NAFU/&
} u^4"96aXJ
spoWdRM2
//日志 >stVsFdV)
public static void log(String sMsg) p'w"V6k('~
{ h1UlLy8
System.err.println(sMsg); KE)D =P
} \i;~~;D
1\.zOq#
CFS3);'<|
public static void log(int sMsg) uJ!s%s2g
{ G:6$P%.
System.err.println(sMsg); %JA&O
} >[P7Zlwv4
} ?U9d3] W
p9] 7g%
F>oxnhp6
/* 5}l#zj
**TestMethod.java 7)6Yfa]I%
*/ lVp~oZC6[
package NetFox; h9OL%n 7m'
Gk]qE]hi
E(4lu%
public class TestMethod { qzbkxQu]g
?GD?J(S
gp&& c,
public TestMethod() \eSk7C
{ ///xx/weblogic60b2_win.exe :`"T Eif
try{ 6xzR*~7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ev|{~U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TWR#MVMI
SiteFileFetch fileFetch = new SiteFileFetch(bean); zl0:U2x7
fileFetch.start(); p31rhe
} SAo\H
catch(Exception e){e.printStackTrace ();} 5`{;hFl
rjf=qh5s
BnnUUaE
} q?]@' ^:;
<W[8k-yOV`
sq6%=(q(?
public static void main(String[] args) {'Qk>G s
{ (l!D=qy
new TestMethod(); g!)LhE
} dK(%u9v
} JE:n`l/p
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