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)); SMIDW}U2S
} m[^)Q9o}
for(int i=0;i<nEndPos.length-1;i++) .d}yQ#5z
{ 4sntSlz)~k
nEndPos = nStartPos[i+1]; 7Mq{Py1
} Il9xNVos#
nEndPos[nEndPos.length-1] = nFileLength; Y,GlAr s4
} CQNMCYjg(R
} <tBT?#C9+
vPGUE`!D+
_@y uaMoW=
//启动子线程 ||Owdw|{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !yPy@eP~
for(int i=0;i<nStartPos.length;i++) OdZ/\_Z
{ e"wzb< b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <" nWGF4d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), br Iz8]
nStartPos,nEndPos,i); #*/nUbsg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;4ybkOD
fileSplitterFetch.start(); Im\ ~x~{
} z,$uIv}'@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S6(48/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @--"u_[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |'1.ajxw
nEndPos = " + nFileLength); v@OELJX
// fileSplitterFetch[nPos.length-1].start(); 7Y[ q)lv
]W$G!(3A
D4@?>ek6U
//等待子线程结束 rh1PpsSc
//int count = 0; N2U&TCc
//是否结束while循环 \1gAWUt('
boolean breakWhile = false; hHTt-x#
-&`_bf%M
E b:iym0
while(!bStop) qbsod
{ K<:%ofB"S
write_nPos(); c5$DHT@N"
Utility.sleep(500); HEbL'fw^s
breakWhile = true; >!@D^3PPA
p<H_]|7$7U
LwRzzgt
for(int i=0;i<nStartPos.length;i++) x}pH'S7
{ G#e]J;
if(!fileSplitterFetch.bDownOver) \t1#5
{ kJJiDDL0;*
breakWhile = false; XJPIAN~l
break; .pWRV<25
} &hkD"GGe
} .tLRY
if(breakWhile) 7Z`4Kdh .
break; a'|]_`36x
&Pm@+ML*x
P$Vh{]4i{
//count++; fsPNxy"_
//if(count>4) ^8~TsK~
// siteStop(); 8 <;.[l
} ?i0+h7=6
DJgM>&Y6,
`Wjq$*
System.err.println("文件下载结束！"); rgCC3TX
} /klo),|&
catch(Exception e){e.printStackTrace ();} zO\_^A|8H
} Bj2iYk_cLa
!{CIP`P1
0J'Cx&Rg
//获得文件长度 Xe\}(O
public long getFileSize() W|@SXO)DY
{ 72xf|s=
int nFileLength = -1; g]HWaFjc5
try{ S+[,\>pY
URL url = new URL(siteInfoBean.getSSiteURL()); ]^.`}Y=`g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {$[0YRNk u
httpConnection.setRequestProperty("User-Agent","NetFox"); Bf00&PE;
2=;ZJ
hfLe<,
int responseCode=httpConnection.getResponseCode(); sj&(O@~R
if(responseCode>=400) r+[g.`
{ K/C}
processErrorCode(responseCode); okRt^qe
return -2; //-2 represent access is error &$CyT6mb^
} ~s4JGV~R
EH2):
lshSRir
String sHeader; ym6Emf]
sq#C|v/
U:$zlfV
for(int i=1;;i++) n8!|}J
{ )E=B;.FH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2i!R>`
//Utility.log(in.readLine()); ~m=Z>4M
sHeader=httpConnection.getHeaderFieldKey(i); I:=!,4S;
if(sHeader!=null) ]wV\=m?z&
{ 2N &B
if(sHeader.equals("Content-Length")) {`2 0'
{ V?JmIor
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pfvb?Hy
break; uv$5MwKU
} $aTo9{M^
} {)r[?%FMgV
else "[["naa
break; 9mMQ
} B &Z0ZWx
} =r]_$r%gR
catch(IOException e){e.printStackTrace ();} oSMIWwg7G
catch(Exception e){e.printStackTrace ();} F'{T[MA
ZT&[:>upR
Uhh[le2 %
Utility.log(nFileLength); j^8Hjg
7SkW!5
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return nFileLength; ?cz7s28a
} rS\mFt X
8sDw:wTC
:+_H%4+
//保存下载信息（文件指针位置） Z] cFbl\ma
private void write_nPos() ]OKKR/:
{ J^` pE^S
try{ )06. dZq\
output = new DataOutputStream(new FileOutputStream(tmpFile)); L~|_)4
output.writeInt(nStartPos.length); .ejC#vB{KM
for(int i=0;i<nStartPos.length;i++) t9W*N\
{ fF/;BSq'
// output.writeLong(nPos); 8j&1qJx)
output.writeLong(fileSplitterFetch.nStartPos); U.^%7.
output.writeLong(fileSplitterFetch.nEndPos); js)E:+{A,
} '2|mg<Ft
output.close(); uh)f/)6
} 96F+I!qC
catch(IOException e){e.printStackTrace ();} ^JIs:\g<<
catch(Exception e){e.printStackTrace ();} QB*AQ5-
} dXt@x8E
yyVJb3n5:!
{2g?+8L$Z
//读取保存的下载信息（文件指针位置） S,+|A)\#
private void read_nPos() * e,8o2C$
{ 9WoTo ,q
try{ 2U+wiE|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,5*<C'9
int nCount = input.readInt(); R<h:>.M
nStartPos = new long[nCount]; "wV7PSbM
nEndPos = new long[nCount]; jw2hB[WR
for(int i=0;i<nStartPos.length;i++) S|RUc}(
{ Jn0L_@
nStartPos = input.readLong(); Fok`-U
nEndPos = input.readLong(); LwQYO'X
} `$;%%/tx
input.close(); MGKSaP;x
} g( eA?
catch(IOException e){e.printStackTrace ();} S^e e<%-
catch(Exception e){e.printStackTrace ();} #{bT=:3a
} +>mU4Fwp
Z79Y$d>G<E
%.IW H9P7
private void processErrorCode(int nErrorCode) |oOA;JC)(
{ pi*?fUg!W
System.err.println("Error Code : " + nErrorCode); F*B^#AZg
} G"<} s mB
~|wh/]{b9
` NvJ
//停止文件下载 %8%0l*n'
public void siteStop() J]*?_>"#8
{ ;ahI}}
bStop = true; JHVesX
for(int i=0;i<nStartPos.length;i++) olDzmy(=W*
fileSplitterFetch.splitterStop(); #|l#
g31\7\)Ir
6O'B:5~[2
} pEGHW;
} ^zS|O]Tx
//负责部分文件的抓取 ZoKXao
**FileSplitterFetch.java Bd13p_V"6
*/ j=b-Y
package NetFox; #5IfF~*i
?B4X&xf.D
Fmrl*tr
import java.io.*; H]f8W]"c[
import java.net.*; M059"X="
-S}^b6WL
Q S.w#"X[
public class FileSplitterFetch extends Thread { Z2\Xe~{
iJ`v3PP
llBW*4'
String sURL; //File URL 24_/JDz
long nStartPos; //File Snippet Start Position tj!~7lo
long nEndPos; //File Snippet End Position _ <pO<S
int nThreadID; //Thread's ID M*jn8OE
boolean bDownOver = false; //Downing is over +@C|u'
boolean bStop = false; //Stop identical !='&#@7u
FileAccessI fileAccessI = null; //File Access interface Xu5^ly8p9q
?[Qxq34
ZEU/6.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^5gB?V,
{ =g^JJpS
this.sURL = sURL; {B6tGLt#bf
this.nStartPos = nStart; `OyYo^+D|.
this.nEndPos = nEnd; :,dO7dJi
nThreadID = id; ApAHa]Ccp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .[:*bo3
} FHu+dZ
=_dqoAF
%MUwd@,
public void run() L{i|OK^e
{ Rlf#)4
while(nStartPos < nEndPos && !bStop) ZzO.s$
{ \>XkK<ye
lWYgIpw
-jsk-,
try{ Jyu*{
URL url = new URL(sURL); {[.<BU-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wS1zd?
httpConnection.setRequestProperty("User-Agent","NetFox"); a<`s'N1G
String sProperty = "bytes="+nStartPos+"-"; k39;7J
httpConnection.setRequestProperty("RANGE",sProperty); &!FWo@
Utility.log(sProperty); s3l:ST
1{X ;&y
zINziAp{
InputStream input = httpConnection.getInputStream(); {B lM<
//logResponseHead(httpConnection); G^Yg[*bJ^$
&ffd#2f`@
q--;5"=S
byte[] b = new byte[1024]; 3DO ^vV
int nRead; Bl)DuCV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Tj*Vk $}0
{ t1tZ:4
nStartPos += fileAccessI.write(b,0,nRead); ;7Y4v`m
//if(nThreadID == 1) dg]: JU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UDz#?ZWnd
} [8Zvs=1
S+(-k0
Od:,r
Utility.log("Thread " + nThreadID + " is over!"); #\fxU:z~r
bDownOver = true; v81H!c.*
//nPos = fileAccessI.write (b,0,nRead); n$T'gX#5
} <U() *0
catch(Exception e){e.printStackTrace ();} xT$9M"
} 42: 6=\
} ;4 ON
gNG_,+=!
]RJcY1
//打印回应的头信息 r|tTDKGQ
public void logResponseHead(HttpURLConnection con) XZFM|=%X
{ _7"G&nZ0
for(int i=1;;i++) Pb^Mc <j
{ ("L&iu\`@
String header=con.getHeaderFieldKey(i); Bzw!,(u/ "
if(header!=null) 4U;6 2 jq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xui.63/
Utility.log(header+" : "+con.getHeaderField(header)); 0 ))W [
else +MfdZD
break; Sc zYL?w^
} GwoN=
} le-Q&*
24 i00s|#
IPhV|7
public void splitterStop() 5h2@n0
{ _#/zH~V%
bStop = true; 2Y@:Vgg
} >f$>Odqe
yJ&`@gB
p|z\L}0
} ^sp+ sr :
M6P`~emX2
@;we4G5
/* Sp=6%3fZ]m
**FileAccess.java [l2ds:
*//文件访问(定位，写) gz?]]-H
package NetFox; ?p8(Uc#73
import java.io.*; 67/&.d!
OA_Bz"
=hO0@w
public class FileAccessI implements Serializable{ zMkjdjb
l25E!E-'b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =;9*gDfD
RandomAccessFile oSavedFile; yqm^4)Dp
long nPos; <I{)p;u1
aD1G\*AFJ
.*N,x0B(
public FileAccessI() throws IOException E K)7g~
{ VE<&0d<
this("",0); m\88Etl@
} o#-K,|-
/^kZ}}9baU
\WnI&nu
public FileAccessI(String sName,long nPos) throws IOException J<<0U;
{ <= xmJx-V
oSavedFile = new RandomAccessFile(sName,"rw"); +|N!(H
this.nPos = nPos; ,[lS)`G
oSavedFile.seek(nPos); ix<sorR H
} k#I4^
S&A, Q'
Xq9n-;%zL
public synchronized int write(byte[] b,int nStart,int nLen) 4{h?!Z*
{ <303PPX^6
int n = -1; d+_wN2
try{ s 9,?"\0Zm
oSavedFile.write(b,nStart,nLen); @"9^U_Qf1z
n = nLen; Efm37Kv5l
} Q3M;'m
catch(IOException e) "0F =txduS
{ }2^_Gaj
e.printStackTrace (); OA\2ja~+
} $DmWK_A
<Q06<{]R8
8$:4~:]/
return n; /Ot=GhN]
} u.t(78N
OKU9v{
dcMWCK
} #HD$=ECcw
x:`]uOp
sglYT!O
/* ;IC:]Zu
**SiteInfoBean.java HB+\2jEE
*/ ;O*y$|+PA
package NetFox; -0 [^w
E>tlY&0[$
2,c{Z$\kn
public class SiteInfoBean { #<X+)B6t
U5; D'G
w`(EW>i
private String sSiteURL; //Site's URL FnN@W^/z
private String sFilePath; //Saved File's Path 85rXm*Df
private String sFileName; //Saved File's Name qNP&f8fH
private int nSplitter; //Count of Splited Downloading File &D "$N"
#2thg{5
Vx5ioA]{
public SiteInfoBean() _cqBp7
{//nSplitter的缺省值为5 1us-ootsjP
//default value of nSplitter is 5 yIBT*,4
this("","","",5); c}a.
} *Z! #6(G
'k=GSb
A2{u("^[6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #>+O=YO
{ b{|Ha3;w
sSiteURL= sURL; Yyq:5V!
sFilePath = sPath; S3V3<4CB
sFileName = sName; w /$4 Rv+S
this.nSplitter = nSpiltter; p/|]])2
ozZW7dveU
$=7[.z&
} 'u }|~u?m
;iJ*.wVq
5CZii=@
public String getSSiteURL() e"u=4nk
{ WQ/H8rOs
return sSiteURL; {=WTAgP
} &?m|PK)I
9NTBdo%u
COe"te
public void setSSiteURL(String value) C%ibIcm y
{ eRkvNI
sSiteURL = value; -~O7.E(ok
} o}&TFhT
gTE/g'3
kB-%T66\
public String getSFilePath() z;6Tp
{ @^8tk3$Y
return sFilePath; bmT_tNz
} X}.y-X#v5J
hqW4.|&\c
VP H
public void setSFilePath(String value) 8<UD#i@:C
{ gPO,Z
sFilePath = value; JivkY"= F
} 7e\g
z1t YD
0|g|k7c{rF
public String getSFileName() GAONgz|ZI
{ FA-""]
return sFileName; ZUJ!
} t]|WRQvy8
1Zc1CUMG
t#tAvwFM8
public void setSFileName(String value) iR;Sd >)
{ 6/`$Y!.ub
sFileName = value; rQ -pD
} (|DmYn!
S'>(4a
+cQGX5 K
public int getNSplitter() iHoQNog-!
{ tsdkpt
return nSplitter; ]~g6#@l
} J%d\ 7
BdcTKC
%n-:mSus
public void setNSplitter(int nCount) C$o#zu q-
{ ydo"H9NOS
nSplitter = nCount; qgd#BJ=
} R)% Jr.U
} +]^6&MqO
Pt~mpRlH
s@^(1g[w`
/* f/t1@d!
**Utility.java 2P9gS[Ub
*/ &WN#HI."]
package NetFox; lhsd39NM
c,a+u
0j*-ZvE)30
public class Utility { N*6Y5[g!\
bF:]MB^VK
|=H*" (
public Utility() o@TxDG
{ t2Dx$vT*&
b0 ))->&2
B. Rc s
} p!^.;c
2 2K:[K
//线程睡眠 DJ?kQ
public static void sleep(int nSecond) e573UB
{ ft oz0Vb
try{ `9QvokD
Thread.sleep(nSecond); ad^7t<a}<
} V?U->0>Z4
catch(Exception e) "Sp+Q&2U
{ | k"?I
e.printStackTrace (); k,o|"9H
} CAg\-*P|
} e%#(:L
6x%uWZa'
//日志 bp G`,[
public static void log(String sMsg) b#%s!
{ ~e<l`rg#
System.err.println(sMsg); 7kmU/(8
} $Lpt2:.((
Bbuy y
lWj{pyZ
public static void log(int sMsg) o~7~S
{ (=:9pbP
System.err.println(sMsg); jUjgxP*7m
} t}LV[bj1u
} 2\h]*x%:
~nk{\ rWO
v;.7-9c*
/* o.yuz+
**TestMethod.java p%) 1(R8qM
*/ AF5.)Y@.
package NetFox; GKf,1kns
RRh0G>*
69{^Vfd;Y
public class TestMethod { #$p&J1
p9w<|ZQ]:
llVm[7
public TestMethod() >?iL_YTX
{ ///xx/weblogic60b2_win.exe emp*j@9
try{ J#DYZ>}Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6XyhOs%/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }RX[J0Prq~
SiteFileFetch fileFetch = new SiteFileFetch(bean); L&3Ak}sh
fileFetch.start(); &Rw4ub3
} p/jC}[$v
catch(Exception e){e.printStackTrace ();} !yAlb#yu
H8d%_jCr
*FoH'\=
} ~"eos~AuW
ZMO7o 1"
JWhi*je
public static void main(String[] args) TR:V7d
{ 9W3zcL8
new TestMethod(); wc7gOrPpm
} 7J@iJW],,
} u0M[B7Q
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