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)); ,2]a<0m
} Qn`Fq,uvL
for(int i=0;i<nEndPos.length-1;i++) v|wO qS
{ gJ?Vk<hp
nEndPos = nStartPos[i+1]; M"E7=J
} oNp(GQ@0
nEndPos[nEndPos.length-1] = nFileLength; Z?)=4|
} CYZ0F5+t
} n0opb [?
0l2@3}e
R_B`dP<"~Y
//启动子线程 Ax'o|RE)x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "w:?WS
for(int i=0;i<nStartPos.length;i++) !c;BOCqa
{ siD/`T&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ObSRd$M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tVhf1TH#
nStartPos,nEndPos,i); Q3 yW#eD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (!0fmL
fileSplitterFetch.start(); tl^![Z
} xH>2$ ;f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #?fKi$fS;L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l@`Do[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i]}`e>fF
nEndPos = " + nFileLength); ]OLe&VRix
// fileSplitterFetch[nPos.length-1].start(); PEPf=sm
/7hC /!@
'ARbJ1a
//等待子线程结束 D\k'Eez
//int count = 0; mcq.*at
//是否结束while循环 ;ji["b
boolean breakWhile = false; PiF&0;
agj_l}=gO
I:edLg1T
while(!bStop) XY!0yAK(!
{ %IK[d#HO
write_nPos(); $n* wS,
Utility.sleep(500); cCO2w2A[*
breakWhile = true; ;Miag'7
!M;><b}=5
>wf.C%
for(int i=0;i<nStartPos.length;i++) k@>y<A{;D
{ @w73U;9\
if(!fileSplitterFetch.bDownOver) 1i/&t[
{ ` *q>E
breakWhile = false; @k3xk1*
break; Y|~+bKa
} 90UZ\{">
} .A apO}{
if(breakWhile) [(m+Ejzi%
break; ][1 iKT
#b94S?dq
n 'E:uXv"
//count++; +MyXIWmD
//if(count>4) #"!q_@b,D
// siteStop(); B3'-:
} Ft 6{g JBG
#TPS?+(
PDkg@#&y,k
System.err.println("文件下载结束！"); T.pc3+B8N
} THY=8&x)
catch(Exception e){e.printStackTrace ();} s5J?,xu
} GGez!?E%
@@d6,=
&*#Obv
//获得文件长度 bDjm:G
public long getFileSize() 1h#e-Oyff
{ L)X[$:
int nFileLength = -1; 7~!F3WT{
try{ nd,2EX<bE
URL url = new URL(siteInfoBean.getSSiteURL()); `&URd&ouJD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J=6( 4>
httpConnection.setRequestProperty("User-Agent","NetFox"); d[`vd^hI
";;Nc>-Y
c0QKx=
int responseCode=httpConnection.getResponseCode(); U?=-V8#M|
if(responseCode>=400) p mUG`8SY
{ OBL2W\{
processErrorCode(responseCode); 7UsU03
return -2; //-2 represent access is error (O"-6`w[
} #:s*Hy=
'a G`qPB
"=,IbC
String sHeader; r<5i
C_;A~iI7
65U&P5W
for(int i=1;;i++) B{!*OC{l
{ ?H!QV;ku
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }///k]_Sh
//Utility.log(in.readLine()); _K3;$2d|R
sHeader=httpConnection.getHeaderFieldKey(i); th%T(D5n
if(sHeader!=null) O96%U$W
{ .4[M7)
if(sHeader.equals("Content-Length")) =0mn6b9-=
{ ={\9-JJhE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cC]lO
break; b}!T!IP}
} v]y=+* A
} EbnV"]1
else s[#_sR`y
break; 95sK;`rE+
} BMb0Pu8
} ;]>a7o
catch(IOException e){e.printStackTrace ();} u1`JvfLrL
catch(Exception e){e.printStackTrace ();} up2wkc8
yH0vESgv
}pKKNZ`[
Utility.log(nFileLength); cH6J:0>W
Hb\['VhzM
Cy6%f?j
return nFileLength; vF9fXY=
} 9JJk\,
DDe`Lb%%
kOQ!]-;
//保存下载信息（文件指针位置） |eK^Yhym
private void write_nPos() %*OQH?pyx}
{ @s0mX3P
try{ |xrnLdng0R
output = new DataOutputStream(new FileOutputStream(tmpFile)); x#fv<Cj4
output.writeInt(nStartPos.length); \f'=
for(int i=0;i<nStartPos.length;i++) s#FX2r3=Fg
{ mXI'=Vo!S
// output.writeLong(nPos); cUTG! P\R
output.writeLong(fileSplitterFetch.nStartPos); ;0-R"c)-
output.writeLong(fileSplitterFetch.nEndPos); a}[rk*QmZ
} bT`et*]
output.close(); 36}&{A
} {/i&o
catch(IOException e){e.printStackTrace ();} ZUS06#t}
catch(Exception e){e.printStackTrace ();} { T?1v*.[
} c"P:p%\m&u
\lK `
9JO1O:W
//读取保存的下载信息（文件指针位置） XQZiJ %'
private void read_nPos() _7 ^:1i~:.
{ qfF2S
try{ ~-'-<-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f |NXibmP
int nCount = input.readInt(); e8{!Kjiz
nStartPos = new long[nCount]; XoGOY|2`6
nEndPos = new long[nCount]; bd[iD?epD]
for(int i=0;i<nStartPos.length;i++) %`lLX/4~
{ x M{SFF
nStartPos = input.readLong(); o90[,
nEndPos = input.readLong(); Pb<6-Jc[
} U5[r&Y D
input.close(); W Haf}.V
} XI"IEwB
catch(IOException e){e.printStackTrace ();} i:H]Sb)<b
catch(Exception e){e.printStackTrace ();} qyjVB/ko
} S 9;FD3
yUs/lI, Q
{Rn*)D9
private void processErrorCode(int nErrorCode) @_?Uowc8
{ zKThM#.Wa
System.err.println("Error Code : " + nErrorCode); #)4p,H
} S~M/!Xb
ps*iE=D
umt(e:3f5
//停止文件下载 -/_hO$|W
public void siteStop() le6eorK8
{ 0Z{u;FI
bStop = true; DPfN*a-P(
for(int i=0;i<nStartPos.length;i++) ,nJCqX~/G
fileSplitterFetch.splitterStop(); $g\p)- aU
/sSM<r]5j
@eYD@!
} f6m h_l
} G<Urj+3/Xo
//负责部分文件的抓取 3&R1C>JS ]
**FileSplitterFetch.java V!s#xXD}
*/ n>,? V3ly
package NetFox; f/{ClP.
f'Rq#b@
d"S\j@
import java.io.*; &UAYYH
import java.net.*; %&wi@ *#
:0p$r pJP
HC"yC;_
public class FileSplitterFetch extends Thread { $|VdGRZ1
qR kPl!5
D4*_/,}
String sURL; //File URL rr2^sQ;_
long nStartPos; //File Snippet Start Position [@NW
long nEndPos; //File Snippet End Position Fe2t[y:8h
int nThreadID; //Thread's ID ;8cTy8
boolean bDownOver = false; //Downing is over ek d[|g
boolean bStop = false; //Stop identical xu@xP5GB^
FileAccessI fileAccessI = null; //File Access interface WA5.qw
#-l+cu{
=[0|qGzg
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &Y3ZGRT
{ @ ZN@EOM$+
this.sURL = sURL; PR%n>a#
this.nStartPos = nStart; P.djR)YI
this.nEndPos = nEnd; $)6x3&]P
nThreadID = id; 0Kg?X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6UU<:KH
} W)L*zVj~
[4+I1UR`
~DS.b-E
public void run() :g{ybTSEe
{ <Vh}d/
while(nStartPos < nEndPos && !bStop) kpMo7n
{ ,M$h3B\;r
zX6Q7Bc
<&tdyAT?&
try{ PgsG*5WQ
URL url = new URL(sURL); *DQa6,b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bnH:|-?q
httpConnection.setRequestProperty("User-Agent","NetFox"); rx@2Dmt6
String sProperty = "bytes="+nStartPos+"-"; B/Ltb^a
httpConnection.setRequestProperty("RANGE",sProperty); 9zm2}6r4
Utility.log(sProperty); 8YQ7XB
DXZZZ[#
,lVQ-qw5
InputStream input = httpConnection.getInputStream(); 2I7|hZ,
//logResponseHead(httpConnection); m=a^t
WwUHHm<v
arvKJmD
byte[] b = new byte[1024]; h+Y>\Cxg
int nRead; a3,A_M}M'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V5gr-^E
{ QY*F(S,\
nStartPos += fileAccessI.write(b,0,nRead); &w:0ad|
//if(nThreadID == 1) 9<o*aFgCa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .R^ R|<x
} WP'.o
%AA-G
+^%)QH>9
Utility.log("Thread " + nThreadID + " is over!"); iDdR-T|
bDownOver = true; V{X/yN.u
//nPos = fileAccessI.write (b,0,nRead); ux)Wh.5
} +o35${
catch(Exception e){e.printStackTrace ();} =&~ K;=:
} 8Nx fYA
} ft~QVe!
4}Lui9
qHPinxewx
//打印回应的头信息 T "#DhEM
public void logResponseHead(HttpURLConnection con) ->Fsmb+R
{ <- R%
for(int i=1;;i++) 7| `_5e
{ t{`uN
String header=con.getHeaderFieldKey(i); Vddod
if(header!=null) SJE!14|e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "V5_B^Gzb]
Utility.log(header+" : "+con.getHeaderField(header)); "![KQ
else #c9MVQ_
break; Q8_5g$X\
} IDdu2HNu
} \w-3Spk*
=FMrVE
Iz&d S?p_
public void splitterStop() Z1p%6f`
{ aM:tg1g
bStop = true; s"~,Zzy@j
} 0*j\i@
DmZ_tuVI
?OGs+G
} 2#8PM-3"
"&\(:#L
n.,ZgLx["
/* .tsXQf
**FileAccess.java ~`5[Li:eP
*//文件访问(定位，写) Xd.y or
package NetFox; COd~H
import java.io.*; )ri'W <l
$?9u;+jIR
w1 A-_
public class FileAccessI implements Serializable{ ;a[3RqmKW
1yeD-M"w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jU}
RandomAccessFile oSavedFile; (1'sBm7F
long nPos; r^Soqom3
$U2Jq@G*
@f-rS{
public FileAccessI() throws IOException X.rbJyKe
{ z;>O5a>z
this("",0); {@s6ly].
} $>Gf;k
[3qJUJM
>f;oY9 {m
public FileAccessI(String sName,long nPos) throws IOException &fnfuU$
{ RG/P]
oSavedFile = new RandomAccessFile(sName,"rw"); Z7Nhb{
this.nPos = nPos; <!X]$kvG
oSavedFile.seek(nPos); 5UQ[vHMqI
} OQDx82E
9~ifST\
W7 +Q&4Y
public synchronized int write(byte[] b,int nStart,int nLen) Z#K0a'
{ Mi`t$hmP
int n = -1; _HAr0R8BY
try{ y;hco
oSavedFile.write(b,nStart,nLen); vVo# nzeZ5
n = nLen; 4ijZQ
} vmW`}FKW
catch(IOException e) 4Cvo^k/I
{ "eI">`!g
e.printStackTrace (); l_fERp#y
} `$/M\aM%
U*T :p>&
vY,]f^F"
return n; ]`}EOS-Q
} w aDJ
Q}#H|@
Z3iX^
} /jOug>s
u#Uc6? E
b~K-mjJI
/* 9(BB>o54r
**SiteInfoBean.java MO79FNH2\
*/ d UiS0Qs}
package NetFox; utw@5
E8We2T[^M
'RCX6TKBnR
public class SiteInfoBean { _?>f9K$1
T9gQq 7(l
;] #Q!
private String sSiteURL; //Site's URL 23`pog{n
private String sFilePath; //Saved File's Path +@#-S
private String sFileName; //Saved File's Name J_XbtCmt
private int nSplitter; //Count of Splited Downloading File {>#4{D00
DFqVZ
, pr ",=
public SiteInfoBean() O[&G6+
{//nSplitter的缺省值为5 =[^_x+x hE
//default value of nSplitter is 5 $qhVow5~
this("","","",5); vlZ?qIDe
} zMN4cBL9m
(8.|q6Nww
n15lX,FI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lD)QB!*v
{ i52:<< 8a
sSiteURL= sURL; 1)=sbFtS
sFilePath = sPath; zDofe*
sFileName = sName; }^B=f_Ag
this.nSplitter = nSpiltter; 8I=migaxP
dD"o~iEC
D|!^8jHj
} _}wy|T&7k&
}))JzrqAe
X2p9KC
public String getSSiteURL() DvvjIYB~
{ d/:zO4v3
return sSiteURL; NFcMh+qnK
} #N"K4@]{
`;!v<@:i2
O WVa&8O
public void setSSiteURL(String value) |^E#cI
{ u4[3JI>
sSiteURL = value; N!F ;!
} "J%/xj
9:tKRN_D
K"r'w8P
public String getSFilePath() \[w82%U
{ &Q"Ox{~W
return sFilePath; M&iA^Wrs
} VZ8HnNAbX
JY tM1d
+kKfx!
public void setSFilePath(String value) xI7;(o"
{ v='h
sFilePath = value; 'WG%O7s.
} 438+zU
7.PG*q
D'Gmua]I
public String getSFileName() tc'`4O]c8
{ c91rc>
return sFileName; *a7&v3X
} .^S#h (A
zl j%v/9
\P_1@sH=
public void setSFileName(String value) <Vk^fV
{ `\:92+
sFileName = value; Zv*Z^; X9
} H`$s63
}w&+H28.#
r~uWr'}a}
public int getNSplitter() qmcLG*^,
{ WX}"Pj/6
return nSplitter; <[2]p\rj
} >*v^E9Y
Pgs^#(^>
P"%i 4-S
public void setNSplitter(int nCount) xoD5z<<
{ \w!G
nSplitter = nCount; fMn7E8.
} mKwhd} V
} qTnfiYG}
XX5 ):1
sH(AsKiNKe
/* >8~+[e
**Utility.java ;SF0}51
*/ `Njv#K} U
package NetFox; !Jw
Af:4 XSO6
y(B~)T~e@
public class Utility { W;coi4
%Ysu613mz
+pJ;}+
public Utility() 9~DoF]TM
{ _gK@),de
)p>BN|L
7'_zJI^
} &3mseU
Pq~"`-h7:
//线程睡眠 BYN<|=
public static void sleep(int nSecond) .}6 YKKqS
{ YBN. waL
try{ pO$`(+q[
Thread.sleep(nSecond); . \*Z:
} kDJ5x8Q#
catch(Exception e) t$8f:*6(*
{ qn#\ro1H
e.printStackTrace (); _JA.~edqM
} \Nu(+G?e
} gM20n^
2As 4}
//日志 Re('7m h~
public static void log(String sMsg) Xd>4n7nb$`
{ lNQt
System.err.println(sMsg); n*%<!\gJ
} &(\z
3=1aMQ
6#On .Q
public static void log(int sMsg) 2"C'Au
{ L$h.VQv+
System.err.println(sMsg); I+w3It
} |HJdpY>Uu
} i)P.Omr
)+Wx!c,mb
HFBGM\R02
/* "/6(
**TestMethod.java X%xX3e'
*/ ;g: TsYwM
package NetFox; &F[/@
3x9O<H}
V< 0gD?Kx
public class TestMethod { }-k<>~FA
@0?Mwy!
Rk56H
public TestMethod() f.rz2)o
{ ///xx/weblogic60b2_win.exe ;RW!l pGjP
try{ Mi9A%ZmP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @"-<m|lM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8HdmG{7.
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ooz+V;#Q
fileFetch.start(); QP)-O*+AA
} ',`iQt!Lx
catch(Exception e){e.printStackTrace ();} Ot(U_rJCi
BV$lMLD{r
gQgG_&xkC
} 49~5U+x;
7_d gQI3y
DIH.c7o
public static void main(String[] args) vL{~?vq6
{ +q"d=
new TestMethod(); /}r%DND'
} \y{Bnp5h
} 9M:wUYHT
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