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)); J]|lCwF
} \dag~b<
for(int i=0;i<nEndPos.length-1;i++) <\cH9D`dE
{ Z"fnjH
nEndPos = nStartPos[i+1]; 2x*C1
} MO$dim>
nEndPos[nEndPos.length-1] = nFileLength; r?=7#/]
} h}_1cev?
} /M "E5
'{:Yg3K
k99ANW
//启动子线程 !*gTC1bvB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a/wkc*}}/
for(int i=0;i<nStartPos.length;i++) \o j#*aL^
{ xBC:%kG~#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IlcFW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rn?:utP
nStartPos,nEndPos,i); }[<eg>9#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :K6(`J3Y"^
fileSplitterFetch.start(); o= %Fh
} uvrfR?%QK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [af<FQ{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZkJYPXdn?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jF\J+:5M
nEndPos = " + nFileLength); I!;#Nk>
// fileSplitterFetch[nPos.length-1].start(); ,e ~@
[T.BK:
.baS mfc
//等待子线程结束 i%~4>k
//int count = 0; :>[;XT<
//是否结束while循环 5)yQrS !{:
boolean breakWhile = false; sQS2U6
~4mgYzOmD`
.#;;pu7W
while(!bStop) fodr1M4J
{ ?7cF_Zvve
write_nPos(); M9@#W"
Utility.sleep(500); M#qZ0JT4
breakWhile = true; *S.2p*Vd
P~0d'Oi
O>Nop5#o
for(int i=0;i<nStartPos.length;i++) 4565U
{ Cse@>27s
if(!fileSplitterFetch.bDownOver) %XqLyeOS
{ s.rS06x
breakWhile = false; I$neE"wW
break; 'H`_Z e<
} 9zkR)C
} eD, 7gC-
if(breakWhile) yoj5XBM
break; r^?%N3
}q(IKH\&
iw(\]tMt
//count++; V\kf6E
//if(count>4) qb ^4G
// siteStop(); v5t`?+e
} 5|-(Ic
G2kr~FG
4\?I4|{pC
System.err.println("文件下载结束！"); ujcNSX*
} PL8eM]XS
catch(Exception e){e.printStackTrace ();} 'B"kUh%3$5
} d& @KGJ
~`MGXd"o
%rTXT
//获得文件长度 9`)NFy?
public long getFileSize() w<awCp
{ N2}].}
int nFileLength = -1; zu}h3n5
try{ %&^F.JTt\
URL url = new URL(siteInfoBean.getSSiteURL()); N L]:<FG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7;n'4LIa9
httpConnection.setRequestProperty("User-Agent","NetFox"); ~"5WQK`@
S{z%Q
.J~iRhVOF
int responseCode=httpConnection.getResponseCode(); #4''Cs
if(responseCode>=400) WW;S
{ XTyn[n
processErrorCode(responseCode); 8*)zoT*A
return -2; //-2 represent access is error (G"b)"Qum
} T.HI $(d
EPr{1Z
U$pHfNTH
String sHeader; awXL}m[_!
{P(Z{9u%
-?!Z/#i4
for(int i=1;;i++) /wCeeG,<
{ ?}B9=R$Pi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a7q-*%+d5
//Utility.log(in.readLine()); +iwNM+K/gQ
sHeader=httpConnection.getHeaderFieldKey(i); 2u6N';jgZ
if(sHeader!=null) DnaG$a<
{ /v;g v[
if(sHeader.equals("Content-Length")) C did*hxJ
{ o)?"P;UhJX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q[q#cY:0
break; KI$?0O
} |zvxKIW;wd
} R6)p4#|i
else $RKd@5XP
break; &tQ,2RT
} 'mug,jM
} ,I@4)RSAH|
catch(IOException e){e.printStackTrace ();} "^<:7_Y
catch(Exception e){e.printStackTrace ();} lV$U!v:b
4%p5X8|\ih
_?@>S7-
Utility.log(nFileLength); &.o}(e:]
~@bCSOIy
?i(Tc!
return nFileLength; pp#Kb 2*
} w])bQ7)
4I^6[{_
F)_Rs5V:(
//保存下载信息（文件指针位置） Ajq;\-:
private void write_nPos() t22BO@gt74
{ n`68<ybl5
try{ kd'qYh
output = new DataOutputStream(new FileOutputStream(tmpFile)); .^djB x
output.writeInt(nStartPos.length); j>?H^fB
for(int i=0;i<nStartPos.length;i++) _QBd3B%
{ kzns:-a
// output.writeLong(nPos); ss,t[`AV{
output.writeLong(fileSplitterFetch.nStartPos); w_,.
output.writeLong(fileSplitterFetch.nEndPos); uiE9#G
} 1w+&Y;d|
output.close(); 5]p>&|Ud
} L|6clGp
catch(IOException e){e.printStackTrace ();} JeUFCWm
catch(Exception e){e.printStackTrace ();} aiw~4ix
} nf/iZ &
%nOBsln
HC4ad0Gs+{
//读取保存的下载信息（文件指针位置） >}u?{_s *0
private void read_nPos() (LRv c!`"
{ jfqWcX.X=
try{ XT~JP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;b cy(Fp,\
int nCount = input.readInt(); 4VaUa8 D
nStartPos = new long[nCount]; c2?(.UV
nEndPos = new long[nCount]; ;csAhkf:S
for(int i=0;i<nStartPos.length;i++) xYM/{[
{ ^lRXc.c z
nStartPos = input.readLong(); x}N+vK
nEndPos = input.readLong(); fPK|Nw]b
} &!/L^Y*+
input.close(); Ax0u \(p<^
} !&E>8h
catch(IOException e){e.printStackTrace ();} cKF02?)TX
catch(Exception e){e.printStackTrace ();} lUCdnp;w'
} %~^R Iwm
[JMz~~F
}%$9nq3
private void processErrorCode(int nErrorCode) IOTHk+w
{ *qY`MW
System.err.println("Error Code : " + nErrorCode); N##3k-0Ao
} $hn_4$
!&SUoa
<B$Lu4b@c
//停止文件下载 9S&6u1
public void siteStop() Mk|h ><Q"
{ '$1-A%e$1
bStop = true; ;N]ElwP
for(int i=0;i<nStartPos.length;i++) 'D\(p,(Mt
fileSplitterFetch.splitterStop(); -Q 6W`*8
cy^6g?ew
;c:vzF~Q
} RJF1~9
} ,UWO+B]
//负责部分文件的抓取 &}:Hp9n
**FileSplitterFetch.java 3{d1Jk/S
*/ wzo-V^+q
package NetFox; fRaVY`|wK
1;vn*w`p
^"6xE nA]
import java.io.*; tPC8/ntP8
import java.net.*; R*Pfc91}
b*dRNu
1ZhJ?PI,9{
public class FileSplitterFetch extends Thread { aKH\8O4L5
@WBy:gV"
UTin0k
String sURL; //File URL [_-CO}>
long nStartPos; //File Snippet Start Position 1#]tCi`
long nEndPos; //File Snippet End Position y7d)[d*Mz
int nThreadID; //Thread's ID te" 8ZmJ
boolean bDownOver = false; //Downing is over 4d0PW#97.
boolean bStop = false; //Stop identical ,W*<e-
FileAccessI fileAccessI = null; //File Access interface ,589/xTA@
z56W5g2
_QY0j%W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8"8sI
{ n8zUL1:R
this.sURL = sURL; S5m1~fz
this.nStartPos = nStart; ~+3f8%
this.nEndPos = nEnd; 6<]&T lS]
nThreadID = id; #0G9{./C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1vl~[
} tEiN(KA!5
Q(Vc/
t4h05i
public void run() M9bb,`X>Q
{ b LL!iz?
while(nStartPos < nEndPos && !bStop) {*jkx,|
{ v8 6ls[lzu
z ; :E~;
7zR7v
try{ z<^HohT
URL url = new URL(sURL); tBrd+}e2*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q9%N>h9
httpConnection.setRequestProperty("User-Agent","NetFox"); VD36ce9
String sProperty = "bytes="+nStartPos+"-"; _e~EQ[,
httpConnection.setRequestProperty("RANGE",sProperty); ^!pagt^
Utility.log(sProperty); 'f;+*~*L
.%WbXs
x0Tb7y`
InputStream input = httpConnection.getInputStream(); 0qJ(3N
//logResponseHead(httpConnection); bG.aV#$FIg
L8R|\Bx
$D9JsUij
byte[] b = new byte[1024]; X5>p~;[9
int nRead; 20%xD e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &~$^a1D6
{ er l_Gg
nStartPos += fileAccessI.write(b,0,nRead); :Q?xNY%
//if(nThreadID == 1) P-^Z7^o-bX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \zj8| +
} 2&$A x
qMI%=@=
J#:%| F%
Utility.log("Thread " + nThreadID + " is over!"); x:sTE u@
bDownOver = true; z${B|
//nPos = fileAccessI.write (b,0,nRead); |!57Z4X
} !8l4Hc8
catch(Exception e){e.printStackTrace ();} J]N-^ld\\
} 4!/{CGP
} *<Qn)Az
3b#KrN'
8uT@$./
//打印回应的头信息 bE]2:~
public void logResponseHead(HttpURLConnection con) Fm[,u
{ uERc\TZ
for(int i=1;;i++) ]dk~C?H
{ _h@e.BtDs
String header=con.getHeaderFieldKey(i); p@r~L(>+3
if(header!=null) 8@b@y|#]X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (q:L_zFj>"
Utility.log(header+" : "+con.getHeaderField(header)); mI"|^!L
else D_@r_^}
break; q'K=Ly+
} r%_)7Wk*
} ZZl)p\r
eT}c_h)
JRU)AMMU&
public void splitterStop() tOp>OoD
{ <5C3c&sds
bStop = true; 4\Q ?4ZX
} ']}ZI 8
aQinR"o
g w}t.3}
} +uv]dD*i
70|Cn(p_
o1I{^7/
/* "MK:y[+*
**FileAccess.java LRB#|PW
*//文件访问(定位，写) (kb^=kw#0
package NetFox; `;QpPSw+
import java.io.*; |3"'>* J
BhdJ/C^
H$1R\rE`
public class FileAccessI implements Serializable{ %3z-^#B=
zy+|)^E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4HkOg)a
RandomAccessFile oSavedFile; f&{2G2O%
long nPos; nJ'O(Wh,)
U.?,vw'aai
=AZ>2P
public FileAccessI() throws IOException m./lrz
{ oryoGy=(yk
this("",0); }1d 6d3b
} C4Bh#C
{!'AR`|
QXgh[9wG
public FileAccessI(String sName,long nPos) throws IOException 3{]i|1&j
{ `4w0*;k;
oSavedFile = new RandomAccessFile(sName,"rw"); >,32~C
this.nPos = nPos; 3Yg/-=U(
oSavedFile.seek(nPos); ^aXyho
} F!'b_gmz
p~+)!Z#
p0'A\@|
public synchronized int write(byte[] b,int nStart,int nLen) vpOzF>O
{ [<f\+g2ct
int n = -1; a.wRJ
try{ H.wp{m{
oSavedFile.write(b,nStart,nLen); dO rgqz`e
n = nLen; [^~Fu9+"
} Ou8@7S
catch(IOException e) X^fMt]
{ }MXZ
e.printStackTrace (); yv4hH4Io
} ldi'@^
VEo>uR
R}>Gk
return n; BE}lzn=sF
} uK}k]x\z
N<Ti[Q]G
!t~S.`vF
} 3vNoD
|2{y'?,
Mq6.!j
/* F~{yqY5]n
**SiteInfoBean.java }_gCWz-5?
*/ a|TP2m
package NetFox; A&F@+X6@
+anNpy
I)Lg=n$
public class SiteInfoBean { 9[6xo!
?&"cI5-
*sZOws<
private String sSiteURL; //Site's URL Ok2k; +l
private String sFilePath; //Saved File's Path D|`[ [
private String sFileName; //Saved File's Name lj'c0k8
private int nSplitter; //Count of Splited Downloading File " 0K5 /9
)#IiHBF
xREqcH,vU
public SiteInfoBean() @6}c\z@AxM
{//nSplitter的缺省值为5 3DMfR ofg
//default value of nSplitter is 5 VX2bC(E'%
this("","","",5); vr=iG xD
} 7GWPsaPn
@j5W4HU
552c4h/T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EJb"/oLla
{ "A,]y E
sSiteURL= sURL; tlI3jrgw
sFilePath = sPath; G5bi,^G7
sFileName = sName; |W`1#sP>
this.nSplitter = nSpiltter; C&Ow*~
[1 w
YeYFPi#
} 8O("o7~"
HQ ^> ~
}4 P@`>e/`
public String getSSiteURL() &6r".\;^
{ H_vOZ0
return sSiteURL; p\b:uy6#
} "xdXHuX
>77 /e@
[[oX$0Fp\!
public void setSSiteURL(String value) WTSY:kvcCY
{ =TwV_Dro~
sSiteURL = value; M2%<4(UwI
} ]^/:Xsk$
KX[_eOL
>bEH&7+@_'
public String getSFilePath() 2 os&d|
{ I6{}S6
return sFilePath; EX=+TOkAf
} =pN?h<dc
=JX.* MEB
Euk#C;uBg
public void setSFilePath(String value) Rfeiv
{ fPZBm&`C
sFilePath = value; qYGnebn@\
} pj?+cy v~
3yZtyXRPn
(ZT*EFhb(
public String getSFileName() ('OPW&fRG
{ LN" bGe
return sFileName; S2;{)"mS
} ,BOB &u
CZxQz
J0C<Qb[
public void setSFileName(String value) }\OLBg/
{ +mMn1&
sFileName = value; e7>)Z
} ()}O|JL:K
xJJlVP
.A&Ey5
public int getNSplitter() +2|X 7wA
{ y%v<Cp@R
return nSplitter; NnGQ=$e
} KaBze67<|
J &u&G7#S
Bl3G_Ep
public void setNSplitter(int nCount) =_D82`p
{ !|}J{
nSplitter = nCount; 9Rb-QI
} &gIu<*u<
} V[rNJf1z
DTlM}
L7wl3zG
/* =LZj6'
**Utility.java $_@~t$
*/ aVO5zR./)
package NetFox; ]J~37 35]
"n7rbh3VW
OzX\s=
public class Utility { `P)1RTVx
w`c9_V
p! zC
public Utility() %R7Q`!@8
{ V7[Dvg:W
d3&gHt2
Jr%u[d>
} |t4k&Dkx`
B[S.6"/H
//线程睡眠 7iLm_#M
public static void sleep(int nSecond) o-lb/=K+
{ }Xrs"u,
try{ \#m;L/D
Thread.sleep(nSecond); g4oFUyk{
} vD[@cm
catch(Exception e) N+"Y@X yg
{ "5synfO
e.printStackTrace (); jE&kN$.7j
} |Rhx&/
} Ty*ec%U9F
E@JxY
//日志 GWM2l?zOP
public static void log(String sMsg) G|4vnIS
{ "of(,p
System.err.println(sMsg); k#c BBrY
} {YcVeCq+N
x98LOO
]^3_eHa^d
public static void log(int sMsg) OcQ_PE5\
{ w>IkC+.?
System.err.println(sMsg); Q2Yv8q_}Uq
} o%Vf#W
} -=Q_E^'
S/G,A,"c
ed'}ReLK
/* ?"{+m
**TestMethod.java ga4 gH>4
*/ 83412@&
package NetFox; )XnG.T{0|
HsR#dp+s~
uZ]B?Z%y#
public class TestMethod { +LV'E#h!Q
2GqPS
28f-8B
public TestMethod() ::j'+_9
{ ///xx/weblogic60b2_win.exe bsuUl*l)
try{ p87s99
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T 2x~fiM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eG"iJ%I
SiteFileFetch fileFetch = new SiteFileFetch(bean); q&<#)#+
fileFetch.start(); /quf'CV}
} W ;P1T"*A
catch(Exception e){e.printStackTrace ();} 'uo`-Y
u5H#(&Om
}<2F]UuR
} ?Ih24>:D
_xl#1>G^J
[l-zU}u&v
public static void main(String[] args) 7v?tSob:b
{ yx{Ac|<mR
new TestMethod(); UciWrwE
} CV]PCq!
} `DG6ollp{
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