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)); 4'+g/i1S F
} Vktc
for(int i=0;i<nEndPos.length-1;i++) %`_Rl>@K=
{ %eE0a4^".
nEndPos = nStartPos[i+1]; .E:3I!dH7
} h-f`as"d
nEndPos[nEndPos.length-1] = nFileLength; qkM)zOZ^
} 'OACbYgG
} 33=lR-N#
EV'i/*v}\
w;{=
//启动子线程 S4_C8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gkM Q=;Nn
for(int i=0;i<nStartPos.length;i++) $} @gR] Z
{ :R{pV7<O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kR+7JUq]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 68?>#o865
nStartPos,nEndPos,i); +SB>>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :R-_EY$k6
fileSplitterFetch.start(); Q}: $F{
} {>3J96
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :cxA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); EY`]""~8v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ${h1(ec8
nEndPos = " + nFileLength); M ZAz= )-
// fileSplitterFetch[nPos.length-1].start(); S}b^_+UbP
hm\UqIt
kaT !
//等待子线程结束 N>H#Ew@2U
//int count = 0; (KLhF
//是否结束while循环 EzeU-!|W
boolean breakWhile = false; :I{9k~
Ygbyia|
[[#R ry
while(!bStop) B1V+CP3t
{ 3#0y.. F
write_nPos(); UQg_y3 #V
Utility.sleep(500); *Fg)`M3g
breakWhile = true; 7w<e^H?
i5,yrPF
HU/2P`DGP
for(int i=0;i<nStartPos.length;i++) 8og8;#mnyr
{ q@^^jlHP
if(!fileSplitterFetch.bDownOver) !,^y!+,Qy
{ x*sDp3f[*
breakWhile = false; <N:)Xf9`
break; S,s#D9NU
} A"O\u=!
} y9N6!M|'y
if(breakWhile) [}=a6Q>)
break; DbSR(:
VRZqY7j}g
95E#
//count++; R/xT.EQ(N
//if(count>4) js9^~:Tw
// siteStop(); PfsUe,*
} @6 a'p
:}R,a=N
y=aWSb2y'
System.err.println("文件下载结束！"); e*yl_iW
} FHSFH>
catch(Exception e){e.printStackTrace ();} t2iQ[`/?~
} ~"\WV4}`v
lNsdbyV'
Qr_0 L
//获得文件长度 e"%uOuIYX
public long getFileSize() oj[~H}>
{ kLF~^/
int nFileLength = -1; lbX YWZ~7
try{ Lq62
URL url = new URL(siteInfoBean.getSSiteURL()); qg/FI#r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Dkx}}E:<
httpConnection.setRequestProperty("User-Agent","NetFox"); BCuoFw)
"L;@qCfhO
%^d<go^
int responseCode=httpConnection.getResponseCode(); $NCR V:J
if(responseCode>=400) 'd|!Hr<2
{ |2=@8_am
processErrorCode(responseCode); 2+/r~LwbK
return -2; //-2 represent access is error dW22v!
} >& 4):
Eyz.^)r
)4h|7^6ji
String sHeader; A.mFa1lH
X`3_ yeQc
gnkeJ}K
for(int i=1;;i++) {P,hH~!
{ %gQUog
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V'gJtF
//Utility.log(in.readLine()); lQiw8qD
sHeader=httpConnection.getHeaderFieldKey(i); &Z3%UOY
if(sHeader!=null) 8f1M6GK?
{ Bd 0oA )i
if(sHeader.equals("Content-Length")) kBLFK3i
{ 6"o=`Sq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c&P/v#U_
break; 1V9AnzwX
} E=CAWj\
} MkHkM
else Q@W!6]*\
break; =)G]\W)m
} 6.a5%:
} 6"+9$nFyW
catch(IOException e){e.printStackTrace ();} ?A3u2-
catch(Exception e){e.printStackTrace ();} o>nw~_ H\
/E2P
Sa%%3_&
Utility.log(nFileLength); # S/n3
_!VtM#G[
zRd.!Rv
return nFileLength; R?;mu^B
} "G~!J\
pKpB
"O-X*>?f
//保存下载信息（文件指针位置） EADN
private void write_nPos() #t;]s<
{ xMNQT.A
try{ 10h;N[
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8V}|(b#
output.writeInt(nStartPos.length); ;N(L,
for(int i=0;i<nStartPos.length;i++) rM^2yr7H
{ 9-V'U\}L
// output.writeLong(nPos); /t`,7y3T
output.writeLong(fileSplitterFetch.nStartPos); +ue1+#
output.writeLong(fileSplitterFetch.nEndPos); ',xUU{5?
} .>#O'Z&q9
output.close(); gOe!GnO
} KO7&dM
catch(IOException e){e.printStackTrace ();} N*hV/"joZ
catch(Exception e){e.printStackTrace ();} 7G^Q2w
} *r[V[9+y-D
kX+9U"` C
:*&c'
//读取保存的下载信息（文件指针位置） `"[qb ?z
private void read_nPos() ,`RX~ H=C
{ tc[z/
try{ =Gu&0f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u8.Tu7~
int nCount = input.readInt(); .)$MZyo
nStartPos = new long[nCount]; z/+{QBen8
nEndPos = new long[nCount]; EPH n"YK
for(int i=0;i<nStartPos.length;i++) +or<(%o @
{ OJ"./*H
nStartPos = input.readLong(); e ><0crb
nEndPos = input.readLong(); 7l$ u.[
} 9unRMvE u
input.close(); {|hg3R~A
} ~##FW|N)
catch(IOException e){e.printStackTrace ();} h@NC#Iod
catch(Exception e){e.printStackTrace ();} |hw.nY]J
} J'sa{/ #
#+p-
P`{$7ST'Hh
private void processErrorCode(int nErrorCode) W90!*1
{ J9!/C#Fm
System.err.println("Error Code : " + nErrorCode); $/C1s"C@O
} q`/J2r+O
W>i%sHH6
zG<<MR/<
//停止文件下载 V4NQcy? H
public void siteStop() ,pI9=e@O/z
{ HUD0 @HQI
bStop = true; $l"%o9ICG
for(int i=0;i<nStartPos.length;i++) /{`"X_.o
fileSplitterFetch.splitterStop(); &.?E[db"h
tm5)x^7
`*B0n>ol,
} f$\O:E=
} &K60n6q{aQ
//负责部分文件的抓取 _qf39fM;\
**FileSplitterFetch.java /q\e&&e
*/ ~a[/l
package NetFox; ,>rvl P
{R-o8N
O+|C<;K
import java.io.*; n<j+KD#a
import java.net.*; Pb>/b\&JS
YLQ0UeDN'
ws5Ue4g|
public class FileSplitterFetch extends Thread { z9[TjTH^}T
WYTqQqQk
#f) TAA
String sURL; //File URL K&%CeUa
long nStartPos; //File Snippet Start Position ~qeFSU(
long nEndPos; //File Snippet End Position tF}^
int nThreadID; //Thread's ID ,G%UU~/a
boolean bDownOver = false; //Downing is over =xIZJ8e
boolean bStop = false; //Stop identical z/xPI)R[
FileAccessI fileAccessI = null; //File Access interface j;y~vX b
M yHv>
pg4pfi^__V
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G2kU_
{ M)+pH
this.sURL = sURL; ^_|kEvk0
this.nStartPos = nStart; Jg[Ao#,==
this.nEndPos = nEnd; =/46;844T
nThreadID = id; vuPNru" 2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W6i{yneW
} Ch>F11kC
wxo
2=NaqHt(
public void run() ) yMrET m
{ :gU5CUm
while(nStartPos < nEndPos && !bStop) 0GrM:Lh y
{ YPI)^ }
c**&,aL
y0mNDze
try{ RSym9t90t
URL url = new URL(sURL); UTyV6~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hk4t #Km
httpConnection.setRequestProperty("User-Agent","NetFox"); {owuYVm
String sProperty = "bytes="+nStartPos+"-"; ( ~5M{Xh
httpConnection.setRequestProperty("RANGE",sProperty); r)'vn[A
Utility.log(sProperty); |} b+$J
\6&Ml]1
`9K5 ;]
InputStream input = httpConnection.getInputStream(); h9ScN(|0y
//logResponseHead(httpConnection); ":Tm6Nj
Yw3'9m^
)ciP6WzzbI
byte[] b = new byte[1024]; W]ca~%r
int nRead; g) u%?T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vz/w.%_g
{ _=s9o/Cn]
nStartPos += fileAccessI.write(b,0,nRead); -Y/i h(I^
//if(nThreadID == 1) O+=%Mz(l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4kM/`g6?,q
} !B%em%Tv
2r!ltG3}
Om0$6O
Utility.log("Thread " + nThreadID + " is over!"); zW%Em81Wd
bDownOver = true; H\ejW@<;h
//nPos = fileAccessI.write (b,0,nRead); mfQ#n!{ZH
} vNGE]+QX
catch(Exception e){e.printStackTrace ();} edp I?
} VjM3M<!g>M
} hHE~/U
h.>SVQzU
b/z-W`gw
//打印回应的头信息 ja_8n["z
public void logResponseHead(HttpURLConnection con) ]WDmx$"&e
{ ^b+>r
for(int i=1;;i++) RtMI[
{ v<!S_7h
String header=con.getHeaderFieldKey(i); kKSGC?d
if(header!=null) xGwImF$r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?8V.iHJk
Utility.log(header+" : "+con.getHeaderField(header)); eTx9fxw
else ux&"TkEp
break; W%g*sc*+
} I1E9E$m5\<
} .Az36wD
E?XaU~cpc
QPx5`{nN
public void splitterStop() %vJHr!x
{ 46A sD
bStop = true; &ry*~"xoh
} c 3QgX4vq
+H2Jhgi
Y7}>yC/GY
} |NfFe*q0;8
^Qs}2%
'9V/w[mI
/* Q4"\k. ?
**FileAccess.java n(F!t,S1i
*//文件访问(定位，写) r.H`3m.0q
package NetFox; )r9 9zdUk
import java.io.*; !uEEuD#
BY6#dlDi
2!/Kt O)i^
public class FileAccessI implements Serializable{ C 5.3[
lhN@,q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V*4Z.3/E5
RandomAccessFile oSavedFile; &F&`y
long nPos; 15g!Q *v
,&t+D-s<f
!!1?2ine
public FileAccessI() throws IOException dE7x SI
{ IK2da@V
this("",0); 2a$.S" ?
} 6Xvpk1
]<f)Rf">:`
a$My6Qa#
public FileAccessI(String sName,long nPos) throws IOException bBjr hi
{ A>@#eyB
oSavedFile = new RandomAccessFile(sName,"rw"); @YI{E*?S
this.nPos = nPos; MgJ6{xzz
oSavedFile.seek(nPos); 7=l~fKu
} \]tBwa
@k?vbq
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public synchronized int write(byte[] b,int nStart,int nLen) Dl;hOHvKk
{ )/;KxaKt
int n = -1; p/h\QG1
try{ Y [`+7w
oSavedFile.write(b,nStart,nLen); ?*fa5=ql
n = nLen; &BVHQ7[
} Lzh8-d=HQ
catch(IOException e) xE1?)
{ bwsKdh
e.printStackTrace (); mk>; 3m*
} RaJTya^
cbzA`b'Mg
N"S`9B1eD(
return n; pi"H?EHk
} ,-pE/3|(
uBm"Xkxe|w
|#TU"$;
} @?,x3\N-
8 1,N92T5
ZoG@"vr2
/* > G\0Z[<v,
**SiteInfoBean.java gQ+]N*.
*/ \`n(JV
package NetFox; l;; 2\mL?
Y6jyU1>
6j%%CWU{~
public class SiteInfoBean { U4!bW
#"gt&t9Q
\]ib%,:YU
private String sSiteURL; //Site's URL 2.q Zs8&
private String sFilePath; //Saved File's Path hY"eGaoF"
private String sFileName; //Saved File's Name 6V;Dcfvi
private int nSplitter; //Count of Splited Downloading File _Id'56N]J!
dN{At-
y~9wxK
public SiteInfoBean() 6$`<Y?
{//nSplitter的缺省值为5 [EAOk=X
//default value of nSplitter is 5 0,Ds1y^
this("","","",5); bfxE}>
} 5nG\J g7
"Lp.*o
W5R/Ub@g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m}]{Y'i]R
{ &;BhL%)}
sSiteURL= sURL; QiPqN$n
sFilePath = sPath; x93@[B*%
sFileName = sName; !nmZ"n|}p
this.nSplitter = nSpiltter; X|of87
>^Nnhnr
?%O>]s
} km%r{
>F$9&s&
QQJGqM3a2
public String getSSiteURL() s9?mX@>h
{ {53FR
return sSiteURL; ]iV]7g8:
} #7uH>\r
+25}X{r$_
#VQZ"7nI@
public void setSSiteURL(String value) VfnL-bDGV
{ W|PAI[N
sSiteURL = value; j=0kxvp
} l)u%`Hcn
j*%#~UFw
R`j"iC2
public String getSFilePath() Pf;OYWST
{ uYC^&siS<s
return sFilePath; 9ihg[k
} W~ yb>+u
Gs:g
1 iH@vd
public void setSFilePath(String value) ']}-;m\
{ Tuvs}
sFilePath = value; *DJsY/9d}'
} WIWo4[(
b_+o1Zy`
0|GYtnd
public String getSFileName() L$ T2 bul
{ ,EQ0""G!
return sFileName; #$WnMJ@
} u(9pRr L
+)c<s3OCE
q;K]NP-_p
public void setSFileName(String value) @&*TGU
{ %Wtf24'o;v
sFileName = value; =ejcP&-V/
} |~9jO/&r
eaRa+ <#u
S'x ]c#
public int getNSplitter() rJ/HIda
{ o$@/@r
return nSplitter; `I7s|9-=
} a~KtH;7<
IADSWzQ@
B>u`%Ry&
public void setNSplitter(int nCount) 8@3=SO
{ >?+Rtg|${
nSplitter = nCount; !.h{/37]
} ruaZ(R[
} b:(+d"S
H{cOkuy
FK BRJ5O
/* p\zqZ=s
**Utility.java 9/"&6,
*/ A1zRzg4I
package NetFox; eC/{c1C
AQ-PHv
\>$zxC_
public class Utility { pj%]t
q/?*|4I
Y%}&eN$r
public Utility() @3n!5XM{EE
{ nOC\ =<Nsg
V lZ+x)E
B7Ket8<J
} 5bb#{?2i
oyVT
//线程睡眠 jTwSyW
public static void sleep(int nSecond) bB@=J~l4
{ W=Syo&;F8
try{ PTHxvml
Thread.sleep(nSecond); cc${[yj)
} \d:Q%S
catch(Exception e) .#y#u={{l
{ C b'|
e.printStackTrace (); \BBs;z[/
} kQI'kL8>
} %@QxU-k_
QFTiE1mGH
//日志 iv`G}.Bo
public static void log(String sMsg) %:C6\4
{ a;$V;3C{b&
System.err.println(sMsg); 2IJniS=[>
} Xau%v5r
o?]Q&,tO
@<DRFP
public static void log(int sMsg) :%sG'_d
{ +1#;s!e
System.err.println(sMsg); K^x{rn.Zf
} Bc!<!
} cLyf[z)W
%lbvK^
@ 2hGkJ-
/* B}qG-}(V
**TestMethod.java (bm> )U=
*/ e# Y{YtE
package NetFox; nZiwR4kM
q?frt3o
6O?zi|J[:
public class TestMethod { x`?>j$
sssw(F
t<Sa;[+
public TestMethod() 0SD'&
{ ///xx/weblogic60b2_win.exe Xf ^_y(?
try{ ttr`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); UR'v;V&Cb\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0%xb):Ctw
SiteFileFetch fileFetch = new SiteFileFetch(bean); ")ys!V9
fileFetch.start(); "3_X$`v"!
} t=lDN'\P
catch(Exception e){e.printStackTrace ();} w[a(I}x
e R[B0;c
O<fy^[r:`
} b4:{PD~Mh
K1YxF
jNbVp{%/S}
public static void main(String[] args) h5P ]`r
{ ;u`8pF!_eE
new TestMethod(); !,$K;L
} Bor_(eL^
} RaLV@>jPm
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