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)); Y/Y746I
} W,Dr2$V
for(int i=0;i<nEndPos.length-1;i++) i8HSYA
{ ~,':PUkiV
nEndPos = nStartPos[i+1]; "P<~bw5
} &B3\;|\
nEndPos[nEndPos.length-1] = nFileLength; [+GQ3Z\
} T_AZCl4d
} k~=-o>}C
|BYD]vK
5W<BEcV\
//启动子线程 zKV{JUpG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =t)eT0
for(int i=0;i<nStartPos.length;i++) 5Y9 j/wA
{ !2&h=;i~V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k7y!!AV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s?%1/&.~
nStartPos,nEndPos,i); YVW!u6W'[6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8-8= \
fileSplitterFetch.start(); #On1Q:d
} L**!$k"{5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XTW/3pB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y'pG'"U]_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U?|s/U
nEndPos = " + nFileLength); (Z`Y
// fileSplitterFetch[nPos.length-1].start(); +oQ@E<)H
M5)6|T
9,,v0tE
//等待子线程结束 P$4?-AZ
//int count = 0; g>f(5
//是否结束while循环 j<L!ONvJ1
boolean breakWhile = false; kV<VhBql!
kP;Rts8JD
Vl9\&EL
while(!bStop) 54}s:[O
{ = )(;
write_nPos(); 8:M~m]Z+|
Utility.sleep(500); tU)+q?Mw
breakWhile = true; W BiBtU
Uw)K[T
3{$cb"5
for(int i=0;i<nStartPos.length;i++) $6oLiYFX;
{ .)W8 U [
if(!fileSplitterFetch.bDownOver) |`O7>(h
{ 45-pJf8F
breakWhile = false; N$=<6eQm
break; @ObsW!g
} Vx#xq#wK
} "ht2X w
if(breakWhile) kF\QO [
break; \<z{@
2+?M(=4
$!fz87-p>
//count++; U\b,W&%P
//if(count>4) % mIq,
// siteStop(); ZMx<:0ai
} ^|gN?:fA}
8Ipyr%l
!A<?nz Uv
System.err.println("文件下载结束！"); {(aJrSE<z
} }S42.f.p
catch(Exception e){e.printStackTrace ();} Ii,L6c
} *?i~AXJm
S*\`LBl"nX
_|s{G
//获得文件长度 _ :][{W#
public long getFileSize() #U6Wv1H{Lp
{ ]*v%(IGK
int nFileLength = -1; zfxxPL'
try{ "2Ye\#BU6
URL url = new URL(siteInfoBean.getSSiteURL()); m$$U%=r>@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Li7/pUq>}!
httpConnection.setRequestProperty("User-Agent","NetFox"); {cG&l:-r
jdoI)J@9H
_/PjeEm $p
int responseCode=httpConnection.getResponseCode(); UHxXa*HyI
if(responseCode>=400) ^LnCxA&QH
{ 0gnr@9,X
processErrorCode(responseCode); vmk c]DC
return -2; //-2 represent access is error YgVZq\AV"
} wtRAq/
7j@TW%FmV\
EJN}$|*Av
String sHeader; q`qbaX\J3
"S6d^
/dtFB5Z"w
for(int i=1;;i++) <ZCjQkka>r
{ EpPKo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U?.VY@
//Utility.log(in.readLine()); jgukW7H
sHeader=httpConnection.getHeaderFieldKey(i); jagsV'o2
if(sHeader!=null) %"{SGp
{ LnM+,cBz
if(sHeader.equals("Content-Length")) glHHr
{ ek3/`]V:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?HU(0Vgn'
break; EXo"F*gW
} B(E+2;!QF
} X&(1DE
else y/ vE
break; l? 7D0
} HjL+Wg
} 'Kc;~a
catch(IOException e){e.printStackTrace ();} @_0XK)pW
catch(Exception e){e.printStackTrace ();} ql^n=+U
dTS7l02
!~PV\DQN
Utility.log(nFileLength); 4fQ<A <2/
2gukK8R$
/2WGo-
return nFileLength; Ptn0;GC
} X8y&|uH
G4]T
Pe~[qETv
//保存下载信息（文件指针位置） ZC@Pfba[`
private void write_nPos() THkg,*;:
{ >pUR>?t"
try{ Jro)
output = new DataOutputStream(new FileOutputStream(tmpFile)); FL9Dz4
output.writeInt(nStartPos.length); 9K~X}]u
for(int i=0;i<nStartPos.length;i++) 0.=dOz r
{ 2w+w'Ag_R
// output.writeLong(nPos); UM3}7|
output.writeLong(fileSplitterFetch.nStartPos); 4Zo.c* BZ
output.writeLong(fileSplitterFetch.nEndPos); Z`T]jm-3
} u{o3
output.close(); :tdN#m6&
} -LhO </l
catch(IOException e){e.printStackTrace ();} *3d+ !#;rG
catch(Exception e){e.printStackTrace ();} lvY[E9I0
} ot($aY,t
n#|ljC
"A6m-xE~
//读取保存的下载信息（文件指针位置） whxTCIV
private void read_nPos() oIrO%v:'!
{ )%dxfwd6
try{ ~}pc&jz>q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J;|a)Nw
int nCount = input.readInt(); %|AebxB'o
nStartPos = new long[nCount]; L`NY^
nEndPos = new long[nCount]; ]l>LU2 sx
for(int i=0;i<nStartPos.length;i++) %<8`(Uu5
{ JlR$"GU
nStartPos = input.readLong(); >mJH@,F:
nEndPos = input.readLong(); +fS<YT
} !mHMFwvS
input.close(); `,QcOkvbC
} Pm&hv*D
catch(IOException e){e.printStackTrace ();} 0v+-yEkw
catch(Exception e){e.printStackTrace ();} 2[j(C
} mX 3p
ZP{<f~;
_NefzZWUJ
private void processErrorCode(int nErrorCode) HxSq&j*F
{ =' uePM")
System.err.println("Error Code : " + nErrorCode); |;:g7eb
} !]5}N^X
Ps!umV
y+3+iT@i
//停止文件下载 CRBj>
public void siteStop() vAp<Muj(a
{ qv& Bai[
bStop = true; ijsoY\V50
for(int i=0;i<nStartPos.length;i++) 8Cs;.>75[
fileSplitterFetch.splitterStop(); (\0 <|pW
Z1#u&oX
XNgcBSD
} I4W@t4bZ
} N=AHS
//负责部分文件的抓取 Jsl2RdI
**FileSplitterFetch.java j$K*R."
*/ >H^#!eaqw
package NetFox; I`zd:o]
W1 k]P.
yQuL[#p
import java.io.*; AtewC Yo
import java.net.*; s$).Z(6
QF)\\D[
1W\E`)Z}]
public class FileSplitterFetch extends Thread { om`T/@_,
DY -5(6X
&\1n=y
String sURL; //File URL MjU|XQS:
long nStartPos; //File Snippet Start Position =*&[K^
long nEndPos; //File Snippet End Position (J[Xryub
int nThreadID; //Thread's ID w8XCU> |
boolean bDownOver = false; //Downing is over 3V<@Vkf5
boolean bStop = false; //Stop identical I]^>>>p$
FileAccessI fileAccessI = null; //File Access interface @^A5{qQ\
<q8@a0e@
PVsKI<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z$e6T&u5B
{ l-Z( ]
this.sURL = sURL; %WgN+A0
this.nStartPos = nStart; `&M,B=E
this.nEndPos = nEnd; Zge(UhZ
nThreadID = id; B1V{3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zz0e4C
} LWyr
maXg(Lu
u.|Z3=?VG
public void run() $@D a|d4
{ y3zP`^
while(nStartPos < nEndPos && !bStop) r-<O'^C
{ }(oeNPM8
b6bs .
r3W3;L
try{ :OG I|[
URL url = new URL(sURL); @1MnJP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Upe}9xf
httpConnection.setRequestProperty("User-Agent","NetFox"); m^k0j/
String sProperty = "bytes="+nStartPos+"-"; xG9Sk
httpConnection.setRequestProperty("RANGE",sProperty); ~SnUnNDm`
Utility.log(sProperty); FTf#"'O
*yu}e)(0
u^1#9bAW8
InputStream input = httpConnection.getInputStream(); {KG6#/%;
//logResponseHead(httpConnection); g8W,Xq+
Y@UkP+{f=
nlwqSXw
byte[] b = new byte[1024]; vADiW~^Q^
int nRead; Zh=arlk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vw;Z0_C
{ 558P"w0"X
nStartPos += fileAccessI.write(b,0,nRead); 5*AXL.2ih
//if(nThreadID == 1) Y%pab/Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hF%M!otcJ-
} =p+y$
]~({;;3o-
Ld4U
Utility.log("Thread " + nThreadID + " is over!"); c-a,__c?hx
bDownOver = true; T@ c~ql
//nPos = fileAccessI.write (b,0,nRead); |9CikLX)7
} " kDiK`i
catch(Exception e){e.printStackTrace ();} *'%V}R[>
} %;PpwI
} ,T$ts
5E]t4"
(|gQ i{8
//打印回应的头信息 ,>GHR{7>(
public void logResponseHead(HttpURLConnection con) dzf2`@8#
{ _BczR:D*
for(int i=1;;i++) Shm> r@C?
{ JU 9GJ"
String header=con.getHeaderFieldKey(i); Gt w>R
if(header!=null) fab'\|Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @~3--
Utility.log(header+" : "+con.getHeaderField(header)); asT-=p_ 0.
else !?2)apM
break; zWHq4@K
} ]c.w+<
} 7]ieBUfS
U7r8FLl
]lB zpD
public void splitterStop() ex3Qbr
{ 18X@0e
bStop = true; +$2{u_m,
} O9=/\Kc
+#O+%!
$.G 7Vt
} 'h>uR|
K/Q"Z*
SN{z)q
/* Ndmt$(b
**FileAccess.java VF]AH}H8I
*//文件访问(定位，写) 8|u4xf<
package NetFox; \2SbW7"/;P
import java.io.*; *Gsj pNr-
@6u/)>rI
LPk@t^[
public class FileAccessI implements Serializable{ s**<=M GK
>)><u4}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QY\k3hiqn
RandomAccessFile oSavedFile; IwYeKN6s
long nPos; PEMkx"h+
q=1 N&#RG
f/Gx}x=
public FileAccessI() throws IOException v.0qE}' |
{ "c^!LV
this("",0); eP{srP3 9
} O zAIz+`
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=BJLj0=N
public FileAccessI(String sName,long nPos) throws IOException V<ESjK8
{ t],a1I.gk
oSavedFile = new RandomAccessFile(sName,"rw"); P_bB{~$4
this.nPos = nPos; W!Tx%
oSavedFile.seek(nPos); $vn6%M[
} rd <m:r
ggso9ZlLu+
iL/c^(1
public synchronized int write(byte[] b,int nStart,int nLen) C.j+Zb1Z(
{ hmy%X`%j
int n = -1; 5_yQI D%Sq
try{ 2y[Q
oSavedFile.write(b,nStart,nLen); JK,MK|
n = nLen; X>(1fra4
} :X2_#qW#C
catch(IOException e) 01kRe
{ qF)J#$4;6
e.printStackTrace (); }F08o,`?
} "N4^ ^~s
?%kgfw@)
u6iW1,#
return n; _H]\
} 'nmGHorp
kk4 |4
e=amh
} CEfqFn3^
?0qVyK_1
#qRoTtMq7
/* u=`H n-(
**SiteInfoBean.java iFIGJS
*/ d3%qYL_+a
package NetFox; c[@_t.%)
srS!X$cec
Bwg(f_[1
public class SiteInfoBean { >a3m!`lq
UB~K/r`.|
<^S\&v1C_
private String sSiteURL; //Site's URL 4KPnV+h"b
private String sFilePath; //Saved File's Path d<c29Y
private String sFileName; //Saved File's Name 0aT:Gy;
private int nSplitter; //Count of Splited Downloading File RhYe=Qh4{p
Jv~R/qaaD
}G4I9Py
public SiteInfoBean() :8S;34Y;
{//nSplitter的缺省值为5 VH7t^fb
//default value of nSplitter is 5 ;@+|]I
this("","","",5); (g6e5Sgi>
} KXKT5E$
?XKX&ws
|# 0'_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <ZT C^=3
{ C-pR$WM:HN
sSiteURL= sURL; ]($ \7+
sFilePath = sPath; !vX4_!%
sFileName = sName; w4L()eP#?=
this.nSplitter = nSpiltter; QQ?t^ptv
bH+NRNI]
k(H&Af+
} fW= N
}6Pbjm*
4!sK>l!
public String getSSiteURL() F .S^KK
{ &C'^YF_^0
return sSiteURL; |E~c#lV
} %9YY \a {
x'EEmjJ
_2KIe(,;
public void setSSiteURL(String value) Wvl~|Sx]
{ ss-W[|cHU
sSiteURL = value; y;o - @]
} AojL4H|
l]G iz&
7U7!'xU
public String getSFilePath() #cQ5-R-1
{ #91^1jyMf
return sFilePath; y)zZ:lyIq
} >5O~SF.
b}TvQ+W]2
V u")%(ix
public void setSFilePath(String value) {Q>OZm\+
{ vom3C9o
sFilePath = value; L9jT:2F
} Kyx9_2
K/9Jx(I,qL
{ <Gyjq
public String getSFileName() [~Ky{:@)[
{ }etdXO_^
return sFileName; _Q:z -si
} ezw*Lo!
DpggZ|J
S ,F[74K
public void setSFileName(String value) yF\yxdUX#
{ JDf>Qg{
sFileName = value; 3;buC|ky
} lU 62$2
+a39 !j 1_
\^6[^\@[
public int getNSplitter() e6MBy\*n
{ \v&zsv\B@
return nSplitter; LEM%B??&5z
} t+w{uwEY
MWme3u)D
/=YNkw5
public void setNSplitter(int nCount) U;/2\Ii
{ 6D Xja_lp
nSplitter = nCount; VwH|ed$
} !Ew ff|v"
} G_?U?:!AC
/pjl6dJ t
q83^?0WD
/* nQQHm6N
**Utility.java EF!J#N2
*/ ;4!H- qZ
package NetFox; K@*+;6y@
;U>nj],uv
YIwa =^
public class Utility { 3N$@K"qM#
Hk;;+'-
e4Nd
public Utility() 1iY4|j;ahV
{ ?:3hp2k<
@=l6zd@
\{`^Q+<
} hy~[7:/<I&
Z@1kx3Wx$
//线程睡眠 h#Z["BG
public static void sleep(int nSecond) ["f6Ern
{ 27fLW&b2
try{ Wz.iDRFl
Thread.sleep(nSecond); Uo >aQk
} .4\I?
catch(Exception e) Y M:9m)
{ 9k ~8n9
e.printStackTrace (); nDdY~f.B
} ~'lT8 n_
} IOZw[9](+
q6F1Rt
//日志 < 8' b
public static void log(String sMsg) r1< 'l
{ yF(9=z"?
System.err.println(sMsg); A#cFO)"
} i'li;xUhZ
Bza<.E=
XiTi3vCe
public static void log(int sMsg) nrKAK^
{ 1"Oe*@`pV
System.err.println(sMsg); V8 8u-
} &zF>5@fM
} n#x_da-m]
]%D!-[C%1
Pv5S k8
/* F%-@_IsG#
**TestMethod.java `f}s<At
*/ z)hK2JD
package NetFox; 3%'`^<-V
e2c'Wab
MS;^:t1`
public class TestMethod { d]e36Dwk
<8 <P,
V.:,Q
public TestMethod() )!27=R/
{ ///xx/weblogic60b2_win.exe 2*V%S/cck
try{ dPu27 "
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _MC',p&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Eh8GqFEM
SiteFileFetch fileFetch = new SiteFileFetch(bean); DQY1oM)D!
fileFetch.start(); .zZfP+Q]8
} 5 NYS@76o7
catch(Exception e){e.printStackTrace ();} 5Jo'h]
S|tA%2z
2x<BU3
} fQib?g/G
M _< |n
0bh 6ay4
public static void main(String[] args) r5s{t4 ;Ch
{ LmJjO:W}^y
new TestMethod(); ~$6` e:n
} \(Rj2
} :;Z/$M16B
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