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)); C5RDP~au
} LDvF)Eg
for(int i=0;i<nEndPos.length-1;i++) =-pss 47
{ JnY3]
nEndPos = nStartPos[i+1]; AQ 7e
} 7RD` *s
nEndPos[nEndPos.length-1] = nFileLength; e?lqs,m@"
} <p0$Q!^dK=
} 8h20*@wSN
-{b1&
]:E]5&VwV}
//启动子线程 '\*Rw]bR|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rrwsj`
for(int i=0;i<nStartPos.length;i++) TcfBfscU
{ Jp-ae0 Ewa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X)f"`$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kdYl>M
nStartPos,nEndPos,i); #1bgV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1v\-jM"
fileSplitterFetch.start(); M*S5&xpX
} T*T.\b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z%OSW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >;3c;nf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4QZy-a*tA
nEndPos = " + nFileLength); B?%D
// fileSplitterFetch[nPos.length-1].start(); j'J*QK&Q
\+AH>I;vO
5PL,~Y
//等待子线程结束 n ~3c<{coZ
//int count = 0; t+(CAP|,
//是否结束while循环 I3x}F$^
boolean breakWhile = false; %<muVRkB\
GyPN)!X@.&
:A{-^qd(
while(!bStop) ,6buo~?W:
{ gq@."wHU
write_nPos(); N8{>M,
Utility.sleep(500); \4p<;$'
breakWhile = true; G\NCEE'A
+Ae.>%}
>SGSn/AJi
for(int i=0;i<nStartPos.length;i++) er#=xqUY
{ X0$_KPn
if(!fileSplitterFetch.bDownOver) 1a!h&!$9
{ T+ t-0k
breakWhile = false; L wu;y@[
break; Fszk?0T
} B&$89]gs|
} ~3YNHm6V
if(breakWhile) 2$ rq
break; y d$37G|n
2Ls<OO
M:SxAo-D2
//count++; "}EbA3
//if(count>4) f\^QV
// siteStop(); `3:%F>
} TatyD**(
*3K"Kc2
Mww]l[1'EL
System.err.println("文件下载结束！"); D{l((t3=T
} NE4fQi?3
catch(Exception e){e.printStackTrace ();} i=a LC*@
} HW G~m:km
`+o.w#cl
YC_^jRB8n
//获得文件长度 FTfA\/tl(;
public long getFileSize() /fq6-;co+
{ PS22$_}
int nFileLength = -1; IXN4?=)I
try{ M5V1j(URE
URL url = new URL(siteInfoBean.getSSiteURL()); %ze1ZWO{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yBj)#m5!
httpConnection.setRequestProperty("User-Agent","NetFox"); K0g:Q*J-
j5O*H_D
~-GDheA
int responseCode=httpConnection.getResponseCode(); 3$cF)5Vf
if(responseCode>=400) -DnK)u\@
{ hrD6r=JT<~
processErrorCode(responseCode); q':wSu u
return -2; //-2 represent access is error <.B s`P
} 8TPm[r]
,f+5x]F?m
9gg,Dy
String sHeader; w0!,1 Ry
kk'w@Sn.(
n:D*r$ C|p
for(int i=1;;i++) ,Tl5@RN
{ .[fz x`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %}!}2s.A
//Utility.log(in.readLine()); n4 @a`lN5g
sHeader=httpConnection.getHeaderFieldKey(i); DV\ei")
if(sHeader!=null) g8"7wf`0k
{ h12wk2@P/]
if(sHeader.equals("Content-Length")) U08?*{
{ vWH>k+9&X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^BX@0"&-
break; RKkI/Z0
} NR&9:?
} *"\Q ~#W
else m[j3s=Gr
break; Z5L1^
} uFWgq::\
} tJPRR_nZv
catch(IOException e){e.printStackTrace ();} )X;cS} yp
catch(Exception e){e.printStackTrace ();} )<F\IM
}Xi#x*-D
7yTe]O
Utility.log(nFileLength); t`,IW{
ZD%_PgiT
YnWl'{[ C
return nFileLength; <WJ0St
} gj,J3x4TK/
y UAn~!s
0s""%MhFI
//保存下载信息（文件指针位置） ';,Bn9rv
private void write_nPos() {7>CA'>
{ Rl4zTAI
try{ `;CU[Ps?]
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7$W;4!BN*
output.writeInt(nStartPos.length); .p(l+
for(int i=0;i<nStartPos.length;i++) \_AEuz3 F
{ &AcFa<U
// output.writeLong(nPos); #L:P R>
output.writeLong(fileSplitterFetch.nStartPos); X,+}syK
output.writeLong(fileSplitterFetch.nEndPos); 6QXQ<ah"
} 6.s?
output.close(); wrYQ=u#Z
} rDX'oP:
catch(IOException e){e.printStackTrace ();} {IHK<aW
catch(Exception e){e.printStackTrace ();} aSkx#mV
} cC^C7AAq^
;kW}'&Ug
YG~ o
//读取保存的下载信息（文件指针位置） UX`DZb+^
private void read_nPos() #6sC&w3
{ *P R_Y=v%
try{ .l=*R7~EU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S<!_ uq
int nCount = input.readInt(); |zq!CLjD@
nStartPos = new long[nCount]; G+ v, Hi1
nEndPos = new long[nCount]; Rgfhs[Z
for(int i=0;i<nStartPos.length;i++) }K80G~O2<
{ ^Lmc%y
nStartPos = input.readLong(); C'czXZtn
nEndPos = input.readLong(); nQ17E{^pR
} :LiDJF
input.close(); Z3So|M{v
} xY'qm8V
catch(IOException e){e.printStackTrace ();} CEuk1$
catch(Exception e){e.printStackTrace ();} M:Y*Tb6w
} O+p-1 C$\
tNuCxb-
j'Y"/<
private void processErrorCode(int nErrorCode) 04PoBv~g
{ .k,Jt+
System.err.println("Error Code : " + nErrorCode); mzE$aFu8
} Mq:'-`
plx/}ah8
~8xh0TSi
//停止文件下载 +lgF/y6
public void siteStop() gMBQtPNM
{ 4m~7 ~-h
bStop = true; Y3$PQwn .P
for(int i=0;i<nStartPos.length;i++) 25a#eDbqi
fileSplitterFetch.splitterStop(); gO:Z6}3vM
'uf2 nUo
^jha:d
} 9c^skNbS
} ,3]?%t0xe
//负责部分文件的抓取 D<bU~Gd,P
**FileSplitterFetch.java { w8 !K
*/ HKiVEg
package NetFox; gJPDNZ*6pk
Ue3B+k9w
?S@R~y0K
import java.io.*; }-{b$6]
import java.net.*; ;4kx>x*H
te;Ox!B&
)y`TymM[F
public class FileSplitterFetch extends Thread { oB0 8
] `B,L*m6
r'd:SaU+
String sURL; //File URL <,@H;|mZ
long nStartPos; //File Snippet Start Position x'2 ,sE
long nEndPos; //File Snippet End Position 4", )zDk
int nThreadID; //Thread's ID O+o;aa6
boolean bDownOver = false; //Downing is over 4aN+}TkH@G
boolean bStop = false; //Stop identical P#[IUXtT
FileAccessI fileAccessI = null; //File Access interface X"k^89y$
'Gl;Ir^
?UZ$bz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :_^0'ULP
{ cK|rrwa0
this.sURL = sURL; b~/Wnp5
this.nStartPos = nStart; AJ\VY;m7F
this.nEndPos = nEnd; D(qHf9
nThreadID = id; P(pd0,%i;a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]HyHz9QkL
} CO:*x,6au
L{2b0Zh'
,TF<y#wed
public void run() Ehb?CnV#J
{ 9V=<| 2
while(nStartPos < nEndPos && !bStop) 8>Du
{ d<^_w!4X}
[_ M6/
Lf^5Eo/ 5A
try{ (Bt;DM#>
URL url = new URL(sURL); J[}gku?C;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &;ZC<?wS
httpConnection.setRequestProperty("User-Agent","NetFox"); Ii~; d3.
String sProperty = "bytes="+nStartPos+"-"; 0{0;1.ZP
httpConnection.setRequestProperty("RANGE",sProperty); PyC;f8n'(
Utility.log(sProperty); (B>)2:T1
TRgY:R_
M8^.19q;
InputStream input = httpConnection.getInputStream(); F2bm+0vOJ
//logResponseHead(httpConnection); e86Aqehle
$R%+*
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byte[] b = new byte[1024]; "JzfL(yt
int nRead; /&D'V_Q`*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v#<\:|XAg
{ %"l81z
nStartPos += fileAccessI.write(b,0,nRead); M'cJ)-G
//if(nThreadID == 1) uX[O,l^}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0\5M^:8i3
} g|ql 5jW
Zk]k1]u*5
3TU'*w &
Utility.log("Thread " + nThreadID + " is over!"); .-.q3ib
bDownOver = true; j7@!J7S
//nPos = fileAccessI.write (b,0,nRead); ljup#:n
} ulH0%`Fi
catch(Exception e){e.printStackTrace ();} V.;:u#{@-Q
} M4TrnZ1D}
} qs!>tw
kF+ZW%6N
ra]!4Kd'
//打印回应的头信息 iD%qy/I/
public void logResponseHead(HttpURLConnection con) cy1\u2x_`
{ MxY50^}(
for(int i=1;;i++) tCZpfZ@+=
{ `GvA241
String header=con.getHeaderFieldKey(i); tCWJSi`IJ
if(header!=null) <^#P6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cwu$TP A>
Utility.log(header+" : "+con.getHeaderField(header)); L3B8IDq
else RI(=HzB
break; 7^B3lC)
} X$BXT
} `Uzs+k-]
rW:iBq
U:qF/%w
public void splitterStop() ?N4A9W9
{ ]dd[WHA
bStop = true; LsQs:O
} n<{aPLQ
&nQRa?3,
mYjf5
} azvDvEWCQZ
nc<qbN
"YuZ fL`bb
/* clHM8$
**FileAccess.java XK1fHfCEa
*//文件访问(定位，写) Tv`_n2J`2
package NetFox; /r-8T>m
import java.io.*; xC)7eQn/R
;)gLjF/F7
--Oprl
public class FileAccessI implements Serializable{ c+1vqbqHG
LlU'_}>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u/}xE7G
RandomAccessFile oSavedFile; GUKDhg,W
long nPos; wjuGq.qIu
e d_m +NM
ll_}& a0G
public FileAccessI() throws IOException fb/qoZ
{ aJI>FTdK
this("",0); l x7Kw%
} Fl<(m
K~USK?Q%
CP +4k.)*O
public FileAccessI(String sName,long nPos) throws IOException Wt(Kd5k0'2
{ ?;Un#6b
oSavedFile = new RandomAccessFile(sName,"rw"); =Qyqfy*@D?
this.nPos = nPos; R3$@N
oSavedFile.seek(nPos); .Nc_n5D6
} Pow|:Lau!
,`<]>;s
Bgf=\7;5
public synchronized int write(byte[] b,int nStart,int nLen) mLJDxh'B
{ $>;a'f~
int n = -1; $;y1Qiel
try{ Cgo9rC~]
oSavedFile.write(b,nStart,nLen); gTnS[
n = nLen; oK)[p!D?0{
} B0v|{C
catch(IOException e) fO#?k<p
{ ,pn)>
e.printStackTrace (); 9MT3T?IS
} 3#9uEDdE
#7+]%;h
^=k{~
return n; A&NqQ V,
} 6>s=CiZB
jSB'>m]
1ADv?+j)A/
} ^L ]B5,}-
N^lAG"Jao[
wajZqC2yg
/* M</Wd{.g"
**SiteInfoBean.java p/N62G
*/ +SyUWoM
package NetFox; b]w[*<f?
0:. 6rp
/V#7=,,
public class SiteInfoBean { #J\s%60pt
Jns/v6
ER_ 3'
private String sSiteURL; //Site's URL Z&A0hI4d
private String sFilePath; //Saved File's Path TQ?#PRB
private String sFileName; //Saved File's Name B_cgWJ*4
private int nSplitter; //Count of Splited Downloading File :Z[(A"dA
~U9q-/(J/
4Ppop
public SiteInfoBean() &;s<dDQK
{//nSplitter的缺省值为5 SAy{YOLtl
//default value of nSplitter is 5 s047"Q
this("","","",5); LaclC]yLU
} \KCWYi]
lr0M<5d=p
zXjwnep
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AxEc^Cof
{ rEmwKZF'
sSiteURL= sURL; \TZ|S,FS
sFilePath = sPath; bH,M,xIL2
sFileName = sName; -8/JP
this.nSplitter = nSpiltter; rfc|`*m}0
k1RV'
/eb-'m
} !O8.#+
pu#[pa
HJ",Sle
public String getSSiteURL() :kt/$S^-
{ .+HcAx{/2
return sSiteURL; mVt3WZa
} ncj!KyU
#hy+ L
<cj}:H *
public void setSSiteURL(String value) <n\i>A3`,S
{ AJdp6@O+
sSiteURL = value; a(f(R&-:$Y
} 'mJ13
R B%:h-t4
4dD2{M
public String getSFilePath() [Teh*CV
{ >e/ r2U
return sFilePath; z>p]/Sa
} ++0rF\&
)T/J
9*DEv0}a^
public void setSFilePath(String value) 5x2L(l-2
{ yuv4*
sFilePath = value; "|hlDe<
} 8+ hhdy*b
6#vI;d[^
` jyKCm.$#
public String getSFileName() &//2eL
{ ;t!9]1
return sFileName; >8(jW
} 'B,KFA<
{"t5\U6cKM
h\FwgkJP
public void setSFileName(String value) 8O9Gs
{ J)Ol"LXV
sFileName = value; c;^A)_/
} (-J<Vy]
R+uw/LG
;?`@"YG)
public int getNSplitter() iu|v9+
{ C5MqwNX
return nSplitter; W "k|K:
} &r:=KT3
+|0t
>:$"a
public void setNSplitter(int nCount) x;(g
{ lC4PKmno
nSplitter = nCount; *Dc@CmBr
} YD9!=a$
} X.eB ;w/}
.`+yo0O:
OJ>iq@>
/* WN\PX!K9
**Utility.java 6+e4<sy[E
*/ ~ aA;<#
package NetFox; t#~XLCE
_*n)mlLln
7@3sUA_Go
public class Utility { \XDmK
[8z&-'J=
cJ/4Gl
public Utility() Yt*vqm[WV
{ 4DM*^=9E
d- kZt@DL=
OpUA{P
} Y;eoTJ
Tyd h9I
//线程睡眠 6]ZO'Nwo
public static void sleep(int nSecond) |6*Va%LYO-
{ {=iyK/Uf
try{ 9(OAKUQ
Thread.sleep(nSecond); ju.OW`GM
} p6Gcts?,
catch(Exception e) ayeCi8
{ Qsji0ikG
e.printStackTrace (); 37jQ'O U
} LihdZ )
} TzY*;
`;/XK,m-
//日志 uY]T:UVk
public static void log(String sMsg) ]5)"gL%H`
{ .<.#aY;N
System.err.println(sMsg); cmIT$?J
} Bq{]Eh0%
[4\aYB9N
u>}zm_
public static void log(int sMsg) ,Z5Fea
{ cd&B?\I
System.err.println(sMsg); Fs)
} qRl/Sl#F
} LuL$v+`
q)k{W>O
OfJd/D
/* v#F-<?Vv
**TestMethod.java $P;UoqG<&
*/ Man^<T%F
package NetFox; 70=(.[^+
0e\y~#-
j/' g$
public class TestMethod { ;h9W\Se
z{/LX \
)mG0g@qOK
public TestMethod() )ji@k(x27q
{ ///xx/weblogic60b2_win.exe 6Hl<,(vn
try{ o?y"]RCM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :~erh}~ps
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gCL{Cw
SiteFileFetch fileFetch = new SiteFileFetch(bean); vnZ4(
fileFetch.start(); dE GX3 -
} Vmtzig3w[
catch(Exception e){e.printStackTrace ();} 506V0]`/
F1J#Y$q~L
IX.sy
} V]m^7^m3
-f 4>MG
82s5VQ6
public static void main(String[] args) pl?kS8#U?
{ k,lqT>C
new TestMethod(); l#ZyB|
} %p*`h43;
} rmQ\RP W
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