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)); #Q$9Eq8"[
} &#;UKk~)Of
for(int i=0;i<nEndPos.length-1;i++) 1_GUi
{ MlS<txFPS
nEndPos = nStartPos[i+1]; ?L{[84GSO
} hQ8/-#LO_
nEndPos[nEndPos.length-1] = nFileLength; Wl::tgU
} P) GBuW
} mjS)*@F
gZ/M0px
/lAt&0
//启动子线程 #/5jWH7U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I^\YD9~=x
for(int i=0;i<nStartPos.length;i++) ]hL 1qS
{ "'II~/9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KQQR"[z&V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1 ljgq]($
nStartPos,nEndPos,i); HtmJIH:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oACuI|b
fileSplitterFetch.start(); JBi<TDm/
} ddlLS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'iUfr@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V:My1R0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <E$5LP;:
nEndPos = " + nFileLength); 'S@C,x%2,
// fileSplitterFetch[nPos.length-1].start(); Qmzj1e$6x
>!`T=(u!
/g@.1z1w
//等待子线程结束 ,C(")?4aJ
//int count = 0; &``;1/J*W
//是否结束while循环 cKFzn+
boolean breakWhile = false; ?sp
*vUKh^="
0(:"q!h
while(!bStop) />K$_T/]
{ &[qLl
write_nPos(); bWUo(B#*I
Utility.sleep(500); ]W-:-.prh
breakWhile = true; Zpl?zI
N;<<-`i
T4o}5sq}S
for(int i=0;i<nStartPos.length;i++) eP[azC"G[
{ Aw9^}k}UfD
if(!fileSplitterFetch.bDownOver) jyLpe2 S
{ f>-OwL($P
breakWhile = false; D|`[ [
break; lj'c0k8
} " 0K5 /9
} )#IiHBF
if(breakWhile) xREqcH,vU
break; >Y)jt*vQ
FU5vo
mi%d([)%<
//count++; YNHn# 98\
//if(count>4) 1ciP+->$
// siteStop(); w*$nG$
} 8WfF: R;
5pE[}@-c9
hY/SR'8
System.err.println("文件下载结束！"); 7PHvsd"]p
} ~*THL0]~
catch(Exception e){e.printStackTrace ();} qmtVk
} B5zu?AG
[1 w
YeYFPi#
//获得文件长度 h*h+VM
public long getFileSize() .+|G`*1<i
{ Pm7,Nq)<>n
int nFileLength = -1; mNWmp_c,1
try{ ?fCLiK
URL url = new URL(siteInfoBean.getSSiteURL()); l J;wl|9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q8P| ]
httpConnection.setRequestProperty("User-Agent","NetFox"); =ni&*&
>umcpkp-h
lmQ!q>N
int responseCode=httpConnection.getResponseCode(); VG q'
if(responseCode>=400) ]^/:Xsk$
{ KX[_eOL
processErrorCode(responseCode); >bEH&7+@_'
return -2; //-2 represent access is error -O^b
} ZTMzL%i
T_y 'cvh
Uj1^?d+b
String sHeader; dB^J}_wp
9\R:J"X
*N[.']#n
for(int i=1;;i++) O&E1(M|*>
{ Y>wpla[kUq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o5i?|HJ
//Utility.log(in.readLine()); r-H~MisL
sHeader=httpConnection.getHeaderFieldKey(i); vA;ml$
if(sHeader!=null) !ck=\3pr
{ $9M>B<]
if(sHeader.equals("Content-Length")) P\*-n"
{ ?dC[VYC\^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ga+\b>C
break; fw|r{#d
} XDz![s
} {jJUS>
else Ep.,2H
break; #xm<|s
} Cdotl$'
} D0us<9q
catch(IOException e){e.printStackTrace ();} =@G#c5H*
catch(Exception e){e.printStackTrace ();} bhnm<RZ
m:/nw,
It(8s)5
Utility.log(nFileLength); yL_-w/a
J &u&G7#S
]i=-/
return nFileLength; 2fFNJ
} Q^b_+M
9Rb-QI
&gIu<*u<
//保存下载信息（文件指针位置） V[rNJf1z
private void write_nPos() ^$`xUKp`pn
{ Rr|VGtg
try{ =LZj6'
output = new DataOutputStream(new FileOutputStream(tmpFile)); $_@~t$
output.writeInt(nStartPos.length); aVO5zR./)
for(int i=0;i<nStartPos.length;i++) 0A9x9l9Wd
{ "n7rbh3VW
// output.writeLong(nPos); OzX\s=
output.writeLong(fileSplitterFetch.nStartPos); `P)1RTVx
output.writeLong(fileSplitterFetch.nEndPos); w`c9_V
} va95/(
output.close(); %R7Q`!@8
} V7[Dvg:W
catch(IOException e){e.printStackTrace ();} />FrMz8;(
catch(Exception e){e.printStackTrace ();} V`pTl3
} X>wB=z5PXK
slDxsb
/49PF:$?
//读取保存的下载信息（文件指针位置） r*0a43mC1
private void read_nPos() U@ALo
{ `(_cR@\
try{ &:S_ewJK7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N+"Y@X yg
int nCount = input.readInt(); "5synfO
nStartPos = new long[nCount]; jE&kN$.7j
nEndPos = new long[nCount]; |Rhx&/
for(int i=0;i<nStartPos.length;i++) Ty*ec%U9F
{ E@JxY
nStartPos = input.readLong(); GWM2l?zOP
nEndPos = input.readLong(); 'R*xg2!i
} !|9$
input.close(); (W5E\hjJ
} 5#80`/w^U
catch(IOException e){e.printStackTrace ();} jMzHs*:
catch(Exception e){e.printStackTrace ();} qaA\.h7
} /21d%T:}
]i8K )/
>|o-&dk
private void processErrorCode(int nErrorCode) mkk74NY
{ c1jHg2xim
System.err.println("Error Code : " + nErrorCode); }2:bYpYQ
} -,TBUWg
m{JiF-=u
Bag2sk
//停止文件下载 E:D1ZV
public void siteStop() SV<*qz
{ v@XQ)95]F
bStop = true; bL)g+<:F
for(int i=0;i<nStartPos.length;i++) #h6(DuViKw
fileSplitterFetch.splitterStop(); Q= + Frsk
.sbU-_ij@U
=<O{t#]
} +y6|Nq
} zv@'x nY]
//负责部分文件的抓取 ojs&W]r0Z
**FileSplitterFetch.java q&<#)#+
*/ /quf'CV}
package NetFox; :0CR=]WM
R`76Ae`R8
H'q&1^w)
import java.io.*; Dr6Br<yi
import java.net.*; 6x]|IWvW
?uU0NKZA
KjZ^\lq'
public class FileSplitterFetch extends Thread { Pl}}!<!<z
[l-zU}u&v
,^26.p$
String sURL; //File URL 6lT1X)
long nStartPos; //File Snippet Start Position l YH={jJ
long nEndPos; //File Snippet End Position ]1)@.b;QR
int nThreadID; //Thread's ID \#LKsQa
boolean bDownOver = false; //Downing is over ,*E%D_
boolean bStop = false; //Stop identical }sPY+ZjV
FileAccessI fileAccessI = null; //File Access interface +(/XMx}a
@!0j)5%
>h[tHM O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException thipfS
{ %f6l"~y
this.sURL = sURL; w?jmi~6
this.nStartPos = nStart; xXA$16kd
this.nEndPos = nEnd; g~FB&U4c
nThreadID = id; XhWMvme
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l]sO[`X
} v0"|J3
I;P?P5H
X-:Ni_O\ty
public void run() M\\TQ(B
{ ])m",8d&T
while(nStartPos < nEndPos && !bStop) Ef%8+_
{ iN`/pW/JE
eb9qg.9Z
n 8AND0a1C
try{ "*+epC|ks
URL url = new URL(sURL); *9j9=N?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *uA?}XEfi
httpConnection.setRequestProperty("User-Agent","NetFox"); K8|6r|x
String sProperty = "bytes="+nStartPos+"-"; g?`D8
httpConnection.setRequestProperty("RANGE",sProperty); 4fzq C)
Utility.log(sProperty); 5CU< ?
"Y(S G
R^1= :<)C
InputStream input = httpConnection.getInputStream(); OiM{@
//logResponseHead(httpConnection); &=$8 v"&^
ngeX+@
EF"ar
byte[] b = new byte[1024]; w2+RX-6Ie
int nRead; LTzf&TZbx5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hXz"}X n
{ 9?,n+
nStartPos += fileAccessI.write(b,0,nRead); F<V zVEx
//if(nThreadID == 1) }Lb];hww1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wv=L_E_
} ,Yi =s;E
I=(O,*+PQ
aj(M{gFq~
Utility.log("Thread " + nThreadID + " is over!"); )&_{m K
bDownOver = true; zE<vFP-1v
//nPos = fileAccessI.write (b,0,nRead); CvbY2_>Nh
} X@~sIUXx9
catch(Exception e){e.printStackTrace ();} {E6W]Mno
} ?ZDx9*f
} sv0kksj
`Z%XA>
*2:)Rf
//打印回应的头信息 Ae ue:u>
public void logResponseHead(HttpURLConnection con) M\`6H8aLn
{ 6bHj<6>MX
for(int i=1;;i++) .*Hv^_
{ A]H+rxg
String header=con.getHeaderFieldKey(i); ^<y$+HcH
if(header!=null) < "~k8:=4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~-W.yg6D{
Utility.log(header+" : "+con.getHeaderField(header)); m.V mS7_I
else 5.GBd_;
break; P92:}" )*>
} g^0
} Z:Kob b
;P2~cQjD;
Jt)<RMQ^R
public void splitterStop() =602%ef\
{ #e8CuS
bStop = true; K[?wP>s
} FfD2 &(-R
29av8eW?3
HnY: gu
} 3_33@MM
X,y$!2QI
%'g/4I
/* u{H_q&1
**FileAccess.java Pyyx/u+?@
*//文件访问(定位，写) brTB /(E
package NetFox; 7XR[`Tn9<
import java.io.*; P `2Rte6s
58v5Z$%--
u[dI81`
public class FileAccessI implements Serializable{ VKR6i
YO,GZD`-o
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pkk0?$l",
RandomAccessFile oSavedFile; niA{L:4
long nPos; ~4\bR
7,+:QY@
)%MBo.NL
public FileAccessI() throws IOException rcyH2)Y/e
{ As)-a5!
this("",0); ,%,}[q?]d
} bjvi`jyL3k
wkIH<w|jb
:$}67b)MO
public FileAccessI(String sName,long nPos) throws IOException ^ )+tn
{ *{-XN
oSavedFile = new RandomAccessFile(sName,"rw"); ~V./*CQ\c
this.nPos = nPos; .5I1wRN49
oSavedFile.seek(nPos); a\%g_Q){
} 0e}LZ,9e
Xt7uCs
D!@c,H
public synchronized int write(byte[] b,int nStart,int nLen) ?iia
{ S8]g'!
int n = -1; 99ZQlX
try{ RKBtwZx>f
oSavedFile.write(b,nStart,nLen); \}<nXn!
n = nLen; ]"YG7|EU
} i\t4TdEx(
catch(IOException e) nKHyq\
{ ?VzST }
e.printStackTrace (); L~0B
} t;4{l`dk
`[:f;2(@
Ng-3|N
return n; Pd@?(WQ
} ^$T>3@rDB
G4=v2_]
9^aMmN&6N2
} :_?>3c}L
GJ((eAS)
2smLv1w@
/* U,+=>ns>
**SiteInfoBean.java CF$^we
*/ y\@XW*_?
package NetFox; 0<P -`|X
R"82=">v
RQh4RUm
public class SiteInfoBean { K}wUM^
A46y?"]/30
k|g~xmI;
private String sSiteURL; //Site's URL IPY@9+]
private String sFilePath; //Saved File's Path R_Z H+@O
private String sFileName; //Saved File's Name #nu?b?X'
private int nSplitter; //Count of Splited Downloading File fYH%vr)
fo5!d@Nv
ikofJl]9
public SiteInfoBean() z}pdcQl#
{//nSplitter的缺省值为5 l9SbuT$U
//default value of nSplitter is 5 hx:x5L>
this("","","",5); \Mi y+<8$
} 9 s>JdAw?
XLzHm&;
~A6QX8a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M~wJe@bc
{ BGUP-_&
sSiteURL= sURL; 8WaVs6
sFilePath = sPath; 7[8PSoo
sFileName = sName; paiF ah
this.nSplitter = nSpiltter; km8[azB o
+='.uc_
j[c|np4k\
} SFh6'v'1N@
Z,Q)\W<'-
c"fnTJXr79
public String getSSiteURL() M#2DI?S@
{ Mb+cXdZb
return sSiteURL; Blf;_e~=[j
} ^Dd$8$?[
DMf:u`<
:GO}G`jY
public void setSSiteURL(String value) ^OYar(
{ \f%jN1z
sSiteURL = value; ~I!7]i]"*?
} QZzi4[-as
N|8TE7- F|
O[q {y
public String getSFilePath() dx:],VB
{ 6R#f 8
return sFilePath; ]X{LZYk
} !R4`ihi1
&{"aD&
;JDxl-~
public void setSFilePath(String value) MT|}[|_
{ 9r8*'.K`Z
sFilePath = value; Q7f\ 5QjT
} gP)g_K(e
&|55:Y87
5H>[@_u+:
public String getSFileName() l*/I ;a$
{ n Hy|
return sFileName; {3!v<CY'
} `|Tr"xavf
k%JwS_F
q]<cn2
public void setSFileName(String value) gNN{WFHQX:
{ \u2p]K>
sFileName = value; aQw?r
} mZ*!$P:vy"
A=E1S{C
sy#CR4X
public int getNSplitter() }<A\>
{ [,$] %|6wt
return nSplitter; 2et7Vw
} MyAi)Mz~o
I=|b3-
tecCU[O
public void setNSplitter(int nCount) hQPiGIs
{ XkOsnI8n
nSplitter = nCount; d\D.l^
} ^q7 fN0"6
} \h?C G_|]
: xB<Rq
/J8y[aa
/* (wnkdI{
**Utility.java ErHbc2
*/ U c$RYPq
package NetFox; K`768%q
9UZKL@KC
jL>IX`,+6
public class Utility { 8(7DW |\
Hq3"OMGq
q:+,'&<D
public Utility() $62!R]C9\
{ O}"VK
pQ!NhzQ
(%YFcE)SRS
} M)#aX|%Mh
-]\UFR
//线程睡眠 v:nm#P%P
public static void sleep(int nSecond) ;1A4p`)
{ yk,o*g
try{ 8dNwi&4
Thread.sleep(nSecond); 7q^osOj"
} y08.R. l
catch(Exception e) |Xlpgdiu
{ :4;ZO~eq!
e.printStackTrace (); F/IXqj
} B{PI&a9~s%
} >A;Mf*E
CMI%jyiX
//日志 bF0y`
public static void log(String sMsg) 4%0eX]
{ #ih(I7prH
System.err.println(sMsg); T'"aStt6
} Np$pz
d@<(Z7|
3Gubq4r
public static void log(int sMsg) T;IaVMFG|d
{ x$tx!%,)/S
System.err.println(sMsg); FO&U{(Q
} 2Xys;Dwx
} k^:)|Z
8vOKm)[%
c,:xm=&
/* aqSHo2]DX9
**TestMethod.java ^OnU;8IC
*/ \!Cix}}1
package NetFox; Gt3V}"B3\
N.vt5WP
AK]{^Hvz
public class TestMethod { ) wtVFG
TL-sxED,,D
(sHqzWh
public TestMethod() y0k*iS e
{ ///xx/weblogic60b2_win.exe GsA/pXx
try{ XCc/\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jeXv)}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *NHBwXg+
SiteFileFetch fileFetch = new SiteFileFetch(bean); SV0E7qX
fileFetch.start(); 71_{FL8
} !o1{. V9q
catch(Exception e){e.printStackTrace ();} =UE/GTbl
G?AZ%Yx
ze@NqCF
} aVNBF`
DK;p6_tT
D~E1hr&Vd>
public static void main(String[] args) a|Io)Qhr
{ eKPxSN Z
new TestMethod(); h,o/(GNnW
} j6]+fo&3
} +P:xB0Tm D
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