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)); mqZK1<r
} _[[0rn$
for(int i=0;i<nEndPos.length-1;i++) eA& #33
{ ta?NO{*
nEndPos = nStartPos[i+1]; aU6l>G`w
} *}]#E$
nEndPos[nEndPos.length-1] = nFileLength; $#rkvG_w
} 'w,gYW
} $`lWW6>P
utmJ>GWSI
dfFw6R
//启动子线程 jRg/N_2'2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :)lS9<Y}
for(int i=0;i<nStartPos.length;i++) y,:WLk~
{ 4M&$wi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,=+t2Bn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =AO (
nStartPos,nEndPos,i); C+'-TLeu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \ ITd\)F%N
fileSplitterFetch.start(); !H\;X`W|~D
} qWH^/o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =DdPwr 0Op
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $IQPB_:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o-bH3Jkb]&
nEndPos = " + nFileLength); #e@NV4q
// fileSplitterFetch[nPos.length-1].start(); _;3,
vb^fx$V
8-@@QZ\N
//等待子线程结束 tU?BR<q
//int count = 0; bD{tsxm[9
//是否结束while循环 \:+\H0Bz
boolean breakWhile = false; w1I07 (
;+DEU0|pe
zg ,=A?
while(!bStop) Z}t;:yhR
{ W(]A^C=/
write_nPos(); I/w;4!+)
Utility.sleep(500); {ENd]@N*
breakWhile = true; 8=$XhC
+(=-95qZ
s'yR2JYv
for(int i=0;i<nStartPos.length;i++) ry|a_3X(I
{ C&yZ`[K
if(!fileSplitterFetch.bDownOver) dm}1"BU<
{ {_b2!!p
breakWhile = false; z6)N![X
break; $,K@xq5
} oz=V|7,
} pyV`O[
if(breakWhile) 2V]a+Cgk
break; |@_<^cV110
Yeg<MrS4D
hV~M!vFxA
//count++; B>1,I'/$.
//if(count>4) dDA8IW![S
// siteStop(); 2->Lz
} .nZKy't
'Y @yW3K
D SX%SE)
System.err.println("文件下载结束！"); NxF:s,a6
} lD0a<L3
catch(Exception e){e.printStackTrace ();} hqln6m
} F5X9)9S
+@]k[9
6~sU[thGW
//获得文件长度 iT:i '\~
public long getFileSize() <lR:^M[v5<
{ %Mj,\J!
int nFileLength = -1; $VQ;y|K+[
try{ w2xD1oK~o
URL url = new URL(siteInfoBean.getSSiteURL()); -ysNo4#e&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /RJ]MQ\*O
httpConnection.setRequestProperty("User-Agent","NetFox"); TO]7cC
2H w7V3q
4`"}0:t.
int responseCode=httpConnection.getResponseCode(); >d`GNE
if(responseCode>=400) c $r"q :\
{ j^#p#`m
processErrorCode(responseCode); x*:VE57,z
return -2; //-2 represent access is error #w%-IhP
} fZpi+I
0^tY|(b3/M
@]IRB1X
String sHeader; {St-
&lU\9
[K,P)V>K
for(int i=1;;i++) b>QdP$>
{ dhA~Yu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "P?O1
//Utility.log(in.readLine()); Dqo#+_v
sHeader=httpConnection.getHeaderFieldKey(i); ]e),#_M
if(sHeader!=null) V-7l+C5
{ cH*")oD
if(sHeader.equals("Content-Length")) [KgO:},c
{ IV!`~\@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sgP{A}4 W
break; yYGs]+
} y+k^CT/u
} 'fl.&"/r
else /0qbRk i
break; pt"9zkPj
} niCK(&z
} nK03xYA
catch(IOException e){e.printStackTrace ();} $.C-_L
catch(Exception e){e.printStackTrace ();} 8#JX#<HEo
sM MtU@<x
tqpO3
Utility.log(nFileLength); XQn1B3k+
^CLQs;zXE
b MD|
return nFileLength; r!fUMDS
} vVSDPlN;
TaD;_)(
BVeMV4
//保存下载信息（文件指针位置） X-nC2[tu'W
private void write_nPos() Jn=;gtD-*
{ nl 'MWP
try{ R+NiIoa
output = new DataOutputStream(new FileOutputStream(tmpFile)); %H\J@{f
output.writeInt(nStartPos.length); 5C1EdQ4S0
for(int i=0;i<nStartPos.length;i++) b9X*2pnWJ
{ 8>[g/%W
// output.writeLong(nPos); G`n $A/9Q
output.writeLong(fileSplitterFetch.nStartPos); 9\hI:rI
output.writeLong(fileSplitterFetch.nEndPos); BZ:tVfg.
} % Q6 za'25
output.close(); M\4`S&
} ;x\oY6:
catch(IOException e){e.printStackTrace ();} e^\e;>Dh>
catch(Exception e){e.printStackTrace ();} sq`Xz8u
} i:aW .QZ.
:sg}e
gm)Uyr$
//读取保存的下载信息（文件指针位置） _xv3UzD
private void read_nPos() L>~Tc
{ ?nW>'z
try{ VSY p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :+Ukwno?/
int nCount = input.readInt(); p}JOiiHa
nStartPos = new long[nCount]; m4@NW*G{
nEndPos = new long[nCount]; A_9^S!
for(int i=0;i<nStartPos.length;i++) DBHy%i
{ 1`7zYW&L
nStartPos = input.readLong(); c$V5E t
nEndPos = input.readLong(); oV:oc,
} ;B=aK"\
input.close(); I2*rtVAP'j
} 6E}9uwQ
catch(IOException e){e.printStackTrace ();} '?9zL*
catch(Exception e){e.printStackTrace ();} &kIeW;X
} _F%`7j
@M"gEeI9
0h@FHw2d
private void processErrorCode(int nErrorCode) x>[]Qk^?q
{ pjFO0h_Y
System.err.println("Error Code : " + nErrorCode); *7Q6b 4~"
} 'vBZh1`p
h) Wp
^-Od*DTL
//停止文件下载 hU#e\L 7
public void siteStop() \A[l(aB
{ TsTc3
bStop = true; }'x;J
for(int i=0;i<nStartPos.length;i++) ,_3hbT8Q
fileSplitterFetch.splitterStop(); O6;"cUv
Tsg9,/vXM
(P)G|2=
} q;'f3Y
} 5^Qa8yA>7
//负责部分文件的抓取 YqX$a~
**FileSplitterFetch.java nzflUR{`-
*/ 1Nt &+o
package NetFox; J3_aHI
)]1hN;Nz
dgw.OXa
import java.io.*; G>V6{g2Q
import java.net.*; `t U
/d3Jd.l!
~gfR1SE
public class FileSplitterFetch extends Thread { KG'i#(u[
3xChik{
sT\:**
String sURL; //File URL |u&cN-}C d
long nStartPos; //File Snippet Start Position Urr%SIakvM
long nEndPos; //File Snippet End Position q\0/6tl_
int nThreadID; //Thread's ID E8# >k
boolean bDownOver = false; //Downing is over @[n#-!i
boolean bStop = false; //Stop identical %T/@/,7h
FileAccessI fileAccessI = null; //File Access interface ?"d$SK"6Z
XNJ4T]><
s\-,RQ1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j#](Q!
{ g":[rXvId
this.sURL = sURL; M5^Y W#e
this.nStartPos = nStart; Q7s@,c!m_
this.nEndPos = nEnd; |9I)YD
nThreadID = id; V%s g+D2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OR<+y~Rv
} 5>x_G#W
`S {&gl
g$nS6w|5H
public void run() bNea5u##
{ |YJ83nSO~
while(nStartPos < nEndPos && !bStop) X,QsE{
{ =kd$??F
:?t~|7O:
;5Sdx5`_
try{ [xMa^A>p
URL url = new URL(sURL); <)VgGjZ-H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1+x" 5<(W
httpConnection.setRequestProperty("User-Agent","NetFox"); S#/%#k103
String sProperty = "bytes="+nStartPos+"-"; d!,t_jM0
httpConnection.setRequestProperty("RANGE",sProperty); )[Y B&
Utility.log(sProperty); Ed9Uw7
%MHb
;P@]7vkff
InputStream input = httpConnection.getInputStream(); OviS(}v4@
//logResponseHead(httpConnection); xnP!P2
J+6zV m
)Z}AhX
byte[] b = new byte[1024]; :KLXrr
int nRead; ,WT>"9+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8Lo#{`
{ d1j9{
nStartPos += fileAccessI.write(b,0,nRead); kBu{ bxL
//if(nThreadID == 1) G=zWhqieh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u^80NR
} k:@DK9 "^
5(1:^:LGK
^t;z;.g
Utility.log("Thread " + nThreadID + " is over!"); T{YZ`[
bDownOver = true; zzqJeIS
//nPos = fileAccessI.write (b,0,nRead); qL(Q1O!
} p9(y b
catch(Exception e){e.printStackTrace ();} ]-fkmnmWX
} NxT"A)u
} Ha'[uEDb
7>vm?a^D2&
kB\{1;
//打印回应的头信息 x(_[D08/TT
public void logResponseHead(HttpURLConnection con) 0#q=-M/?`
{ N##`
for(int i=1;;i++) bDI%}k9#
{ @f!X%)\;x
String header=con.getHeaderFieldKey(i); :6^7l/p
if(header!=null) TkbaoD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EY}:aur
Utility.log(header+" : "+con.getHeaderField(header)); $vO&C6m$
else %u -x9
break; jmok]-pC
} *GP2>oEM
} hsZ/Vnn`
YO6BzS/~
[}RoZB&I
public void splitterStop() my=f}%k=
{ Yo-}uTkw
bStop = true; DSGcxM+
} ZykMri3bi
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rr<E#w
} yU$MB,1
4ls:BO;k]
V7ph^^sC}
/* ITu19WG
**FileAccess.java &hCbXs=
*//文件访问(定位，写) iyskADS
package NetFox; "L~(%Nx3
import java.io.*; L74Mz]v
%|Ps|iV
~z,o):q1}
public class FileAccessI implements Serializable{ OWd'z1Yl
!-gU~0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DE?v'7cmA
RandomAccessFile oSavedFile; ?RRO
long nPos; n|`3d~9$&
"4j~2{{F
%H{p&ms
public FileAccessI() throws IOException 4s\spvJ
{ >r.]a`
this("",0); pYO =pL^Q
} ;*K4{wvG
JAbUK[:K
VYyija:
public FileAccessI(String sName,long nPos) throws IOException *kr/,_K
{ eH&F gmU
oSavedFile = new RandomAccessFile(sName,"rw"); %36x'Dn?
this.nPos = nPos; ^l &lwSRVt
oSavedFile.seek(nPos); N2r zHK
} x)5}:b1B=
GAGS-G#
|dRVSVN
public synchronized int write(byte[] b,int nStart,int nLen) qTO6I5u
{ LiJYyp
int n = -1; 7]{g^g.9-
try{ ZbnAAbfKH
oSavedFile.write(b,nStart,nLen); *MF9_V)8V
n = nLen; vSzpx
} j0=6B
catch(IOException e) Aq i:h]x
{ ju~$FNt8R
e.printStackTrace (); 9>}&dQ8
} q*!R4yE;C
Hq@+m!
sJHVnMA
return n; ]TV_p[L0B
} ^$c#L1 C
%L|fTndKH
h$S#fY8
} L3&Ys3-h
\ovs[&
sqkWQ`Ur
/* \i.]-k
**SiteInfoBean.java bzN[*X|
*/ *D5 xbkH=.
package NetFox; [-~pDkf:
K7}.#*% ~
{q>%Sr]9
public class SiteInfoBean { 0Tj,TF
V"Q\7,_k.
+{UY9_~\3
private String sSiteURL; //Site's URL *A-_*A
private String sFilePath; //Saved File's Path Z)!8a$M~
private String sFileName; //Saved File's Name *&U~Io"U
private int nSplitter; //Count of Splited Downloading File 9>RkFV
An2>]\L
h5?^MRZS
public SiteInfoBean() ?Uql30A
{//nSplitter的缺省值为5 Hv6h7-
//default value of nSplitter is 5 >?g@Nt8
this("","","",5); ?sfqg gi
} yT^x0?U
?m7:@GOE1
;zCUx*{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8SRR)O[)}
{ eORXyh\K
sSiteURL= sURL; W"\~O"a
sFilePath = sPath; y)kxR
sFileName = sName; Nd8>p.iqO
this.nSplitter = nSpiltter; }'[>~&/"
:Cq73:1\B
wAh]C;+{
} *85N_+Wv!
+!lDAkW0
VL%. maj
public String getSSiteURL() fWHvVyQ.
{ pcMzLMG<
return sSiteURL; Ft5A(P >
} d/_D|ivZ=
;|Cdq
Q)75?mn
public void setSSiteURL(String value) !73y(Y%TE
{ 9r%fBiSk
sSiteURL = value; 161P%sGx2
} j6%W+;{/pj
$;v! ,>
AVT% AS
public String getSFilePath() M}] *j
{ Hq.rG-,p
return sFilePath; _8G w Mj
} RELNWr
>u=
e=;A3S
public void setSFilePath(String value) )KZMRAT-
{ 5CK+\MK
sFilePath = value; 4DL;Y
} 2"&GH1
RV~t%Sw^
a1pp=3Pd?~
public String getSFileName() fcq8aW/z_
{ dD,}i$
return sFileName; 1!uBzO6/$
} s|%R
suEK;Bk9
/8;m.J>bf
public void setSFileName(String value) T"xJY#)}
{ 7z?;z<VJ
sFileName = value; T0 K!Msz
} |r~u7U\
l'I:0a 4T
sVx}(J
public int getNSplitter() |]-Zz7N)
{ _X#Rv2a
return nSplitter; Q`F1t
} 1(p:dqGS
DS?.'"n[u
>YI Vi4''
public void setNSplitter(int nCount) !E$$FvL
{ tV!?Ol
nSplitter = nCount; "Z&.m..gc
} j(%N.f6
} 1$b@C-B@g
tp`1S+'~j
z}E_wg
/* R;DU68R
**Utility.java i#-v4g
*/ ^/BGOBK
package NetFox; `,]Bs*~
-,bnj^L
#gbB// <
public class Utility { d-b04Q7DQ
3}nk9S:jr
,D{7=mDVm
public Utility() ;M?)-dpZ
{ [v~,|N>w
7}&:07U
l@);U%\pS
} xFF!)k #
m?kiGC&m
//线程睡眠 'dwW~4|B
public static void sleep(int nSecond) JY
{ /x49!8
try{ ;MN$.x+
Thread.sleep(nSecond); yX!u&
} !Ubm 586!
catch(Exception e) [Vs\r&qL
{ (p2`ofj
e.printStackTrace (); 1gHe$dzXk
} ]c>@RXY'
} D;YfQQr
qA[lL(
//日志 | In{5Ek
public static void log(String sMsg) [e><^R*u
{ `4*I1WZW
System.err.println(sMsg); _=$~l^Y[
} %"`p&aE:
&ZD@-"@
B_d\eD
public static void log(int sMsg) gC?}1]9c
{ v*.R<-X:
System.err.println(sMsg); b/_Zw^DPC
} hJM&rM7
} cb_C2+%8NA
-jJhiaJ$<
|5vcT,A
/* p-$C*0{
**TestMethod.java O}"oz3H
*/ StJb-K/_cL
package NetFox; 6Rfv3
/[TOy2/;%b
s*GZOz
public class TestMethod { ]~;*9`:
6SCjlaGW5
M@TG7M7Os
public TestMethod() =>'8<"M5z
{ ///xx/weblogic60b2_win.exe 9(]_so24,
try{ VVQ~;{L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Qm[((6}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {jD?obs
SiteFileFetch fileFetch = new SiteFileFetch(bean); LGL;3EI
fileFetch.start(); Ij(dgY
} [j@ek
catch(Exception e){e.printStackTrace ();} A'w+Lc.2
j#f/M3
!5dn7Wuj
} u[qy1M0
lH3.q4D 5
#<Y.+:
public static void main(String[] args) aX.BaK6I
{ ?`TJ0("z"
new TestMethod(); MNs<yQ9I'
} ++~ G\T9H
} Q3>qT84
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