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)); }v$T1Cw
} 8B"my\
for(int i=0;i<nEndPos.length-1;i++) |p"4cG?)
{ M F_VMAq
nEndPos = nStartPos[i+1]; 5l,Q=V^@l
} yE>f.|(
nEndPos[nEndPos.length-1] = nFileLength; $,DX^I%!
} 0{zA6Xu
} +E8}5pDt
e_z"<yq
^e4y:#Nu
//启动子线程 IP-}J$$1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jSMs<ox
for(int i=0;i<nStartPos.length;i++) [X=J]e^D
{ ;&?l1Vu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^iz2=}Q8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w/Ej>OS
nStartPos,nEndPos,i); h&Q9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O({vHqN>
fileSplitterFetch.start(); HS[N]'dc
} t]PO4GA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UCDvN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]CZ&JL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZW>?y$C+
nEndPos = " + nFileLength); {H$m1=S
// fileSplitterFetch[nPos.length-1].start(); BBUXoz
i=DoK{`L
8"2X 8C8
//等待子线程结束 .pd_SQ~
//int count = 0; L7 f'
//是否结束while循环 WzxDnd<B
boolean breakWhile = false; 50J"cGs~
Q?"-[6[v
@o6^"
while(!bStop) 53jtwklA
{ o;<oXv
write_nPos(); Xh*p\ $
Utility.sleep(500); n]]!:jFC
breakWhile = true; ;zZGV4Qc~
FdVWj 5 $a
+5C*i@v
for(int i=0;i<nStartPos.length;i++) )Og,VXEB
{ '@Q aeFm
if(!fileSplitterFetch.bDownOver) oP( Hkp,'
{ ee5QZ,
breakWhile = false; 8`j;v>2
break; l: X]$2;
} u%`4;|tI
} 8E9W\@\
if(breakWhile) 2(Ez H
break; _O*"_^6
@vcvte
Tl ?]K
//count++; 2~BId&]
//if(count>4) 3cztMi
// siteStop(); <u9U%Vsi
} %}%vey
d,0Yi u.p
Mb#-I GZ
System.err.println("文件下载结束！"); l<l6Ey(
} eE'2B."F
catch(Exception e){e.printStackTrace ();} =5yI>A0
} kb>/R/,9
gbJz5EEq
]\Tcy[5
//获得文件长度 U]h5Q.<SG
public long getFileSize() L8zY?v(bG
{ ?MhY;z`=
int nFileLength = -1; |Skxa\MI
try{ #[a+m
URL url = new URL(siteInfoBean.getSSiteURL()); 8`/nk`;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (!^(74
httpConnection.setRequestProperty("User-Agent","NetFox"); ua-cX3E
(8*& 42W
G()- NJ{
int responseCode=httpConnection.getResponseCode(); aH1mW;,1u
if(responseCode>=400) RW@sh9
{ k 8Swra?j
processErrorCode(responseCode); k!lz_Y
return -2; //-2 represent access is error /o19/Pvwm
} kN)m"}gX
=os%22*
UEvRK?mm=
String sHeader; J}-,!3qxW
!a[1rQH
Yy"05V.
for(int i=1;;i++) ^|(w)Sy
{ -$]Tn#`Fb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?r,lgaw
//Utility.log(in.readLine()); D%0GXUp
sHeader=httpConnection.getHeaderFieldKey(i); )D:I@`*
if(sHeader!=null) N}*|*!6hI
{ K] ^kUN_
if(sHeader.equals("Content-Length")) M)U 32gI:
{ x@I(G "
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U&D"fM8
break; _"PTO&E
} h>6'M
} $Qv+*%c
else H?P:;1A]c
break; C NNyz$
} mGXjSWsd
} ^]$x/1I;
catch(IOException e){e.printStackTrace ();} kphv)a4z=
catch(Exception e){e.printStackTrace ();} ( *(#;|m
^fLePsmd
\wxS~T<&L
Utility.log(nFileLength); ]Xur/C2A
R18jju>Zr
;^Vsd\ac0
return nFileLength; K>h=
} 8gv\`
!`k{Ga
T'cahkSw'O
//保存下载信息（文件指针位置） T #&9|
private void write_nPos() `o6Hm
{ ;R E|9GR
try{ `5[d9z/6
output = new DataOutputStream(new FileOutputStream(tmpFile)); HXTBxh
output.writeInt(nStartPos.length); (Id]'w4
for(int i=0;i<nStartPos.length;i++) af61!?K
{ ey@]B5
// output.writeLong(nPos); DHO6&8S
output.writeLong(fileSplitterFetch.nStartPos); 9=j"kXFf
output.writeLong(fileSplitterFetch.nEndPos); 2NLD7A
} ^G+1nY4?J
output.close(); :!M/9D*}0
} 2<Tbd"x?
catch(IOException e){e.printStackTrace ();} z O
catch(Exception e){e.printStackTrace ();} 8I)66
} c|lo%[]R!
;/fZh:V2
GNzkVy:u
//读取保存的下载信息（文件指针位置） yVvO!
private void read_nPos() [a;U'v*
{ J~6+zBF
try{ Vf#X[$pc/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W>Eee?
int nCount = input.readInt(); #YM5P
nStartPos = new long[nCount]; njveZav
nEndPos = new long[nCount]; r^mP'#
for(int i=0;i<nStartPos.length;i++) 8,pnm
{ hBf0kl
nStartPos = input.readLong(); l+'@y (}Q
nEndPos = input.readLong(); K14e"w%6rs
} .(OFYK<
input.close(); Gpws_jw
} $DZ\61
catch(IOException e){e.printStackTrace ();} 2r2qZ#I}
catch(Exception e){e.printStackTrace ();} 05mjV6j7m
} 0b9;vlGq$
PpD ?TAlA
nc#}-}`5
private void processErrorCode(int nErrorCode) vT V'D&x2
{ 3%Z:B8:<y
System.err.println("Error Code : " + nErrorCode); tr6<89e(o
} r#^/qs(~
{ as#lHn
PG<tic<?
//停止文件下载 [R[]&\W
public void siteStop() n0_q-8r
{ R _WP r[P
bStop = true; CfKvC
for(int i=0;i<nStartPos.length;i++) (+d7cln
fileSplitterFetch.splitterStop(); +85i;gO5
=m.Lw
FUic7>
} =T'N6x5@
} nqNL[w6{
//负责部分文件的抓取 *HFRG)[V
**FileSplitterFetch.java q~68)D(
*/ CM+Nm(|\,
package NetFox; K,{P b?
'M>QA"*48E
LeDty_
import java.io.*; 3-z;pk
import java.net.*; ]zEatY
1*\JqCR
p R=FH#
public class FileSplitterFetch extends Thread { 9P;}P!W
e^)+bmh
N t]YhO
String sURL; //File URL k%|7H,7
long nStartPos; //File Snippet Start Position *Y"Kbn6
long nEndPos; //File Snippet End Position o2
int nThreadID; //Thread's ID XKD0n^L[
boolean bDownOver = false; //Downing is over h.PVRAwk
boolean bStop = false; //Stop identical 36mp+}R#
FileAccessI fileAccessI = null; //File Access interface We&~]-b AW
(jbHV.]P9
oc+TsVt
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h>AK^fX
{ F?#^wm5TZ
this.sURL = sURL; 6-8,qk
this.nStartPos = nStart; K.s\xA5`_
this.nEndPos = nEnd; qdkhfm2(K
nThreadID = id; Bw _^"e8X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'B dZN
} &[u%ZL
U$+EUDFi3_
77D>;90>?
public void run() jFbj)!;
{ H9}z0VI
while(nStartPos < nEndPos && !bStop) ;}v#hKC~
{ "M#A `b
jdz]+Q`jq
86pujXjc'
try{ m)l<2`CM
URL url = new URL(sURL); B:Y"X:Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O@*^2, 6
httpConnection.setRequestProperty("User-Agent","NetFox"); oasp/Y.p
String sProperty = "bytes="+nStartPos+"-"; |>_e&}Y%L
httpConnection.setRequestProperty("RANGE",sProperty); \*x'7c/qg
Utility.log(sProperty); rCt8Q&mzf
i\~@2
3@#WYvD
InputStream input = httpConnection.getInputStream(); Er /:iO)_
//logResponseHead(httpConnection); :;Z?2P5i
D d['e
*AK{GfP_
byte[] b = new byte[1024]; ]fxYSm
int nRead; !1G6ZC:z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L@9@3?
{ og0su
nStartPos += fileAccessI.write(b,0,nRead); \ZNUt$\
//if(nThreadID == 1) `sW+R=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zt&"K0X|
} /e|vz^#+1,
X5[.X()M4
v\&C]W]
Utility.log("Thread " + nThreadID + " is over!"); %?<Y&t
bDownOver = true; D,R"P }G
//nPos = fileAccessI.write (b,0,nRead); >3aB{[[N
} \ @XvEx%
catch(Exception e){e.printStackTrace ();} B^|^hZZ>
} vndD#/lXq
} CMu/n]?c
ckDWY<@v
t`F<lOKj
//打印回应的头信息 >|j8j:S[
public void logResponseHead(HttpURLConnection con) i|N%dl+T=
{ :$k];
for(int i=1;;i++) l!S}gbM
{ Bs?B\k=
String header=con.getHeaderFieldKey(i); eKpWFP0
if(header!=null) i&K-|[3{g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4~8!3JH39
Utility.log(header+" : "+con.getHeaderField(header)); Dk^,iY(u
else su2|x
break; E4}MU}C#[
} 2!@ER i
} hYvWD.c}
]lQLA IQ
A^L8"
public void splitterStop() py-5 :g}d
{ n1Ic[cM}
bStop = true; #_(t46
} @%"+;D
3lh^maQ]
M\m6|P
} ,a6Oi=+>/U
b=87k
9nGS"E l{
/* PiL[&_8g
**FileAccess.java Hl|EySno
*//文件访问(定位，写) w'i8yl bZ
package NetFox; {OIktG2gZ
import java.io.*; {tKi8O^Rb
%[l#S*)~
TyGsSc
public class FileAccessI implements Serializable{ \I-bZ|^
n0 q$/Y.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Jxo#sV-
RandomAccessFile oSavedFile; U"T>L
long nPos; s[dq-pc"
+.3,(l
a_V.mu6h6p
public FileAccessI() throws IOException S\jIs[Dz
{ 9coN >y
this("",0); }57d3s
} bVgmjt2&>
#Y_v0.N
E9N.b.Q)
public FileAccessI(String sName,long nPos) throws IOException *B*dWMh
{ -|cB7P
oSavedFile = new RandomAccessFile(sName,"rw"); !'5t(Zw5
this.nPos = nPos; ^U;r>[T9h
oSavedFile.seek(nPos); f53WDI6
} eVvDis
h0c&}kM
-~+Y0\%E
public synchronized int write(byte[] b,int nStart,int nLen) a +lTAe
{ @%[ dh@oY
int n = -1; 0}4FwcCr\
try{ 8GKqPS+
oSavedFile.write(b,nStart,nLen); du5|/
n = nLen; u27*-X 5
} BpR#3CfW
catch(IOException e) )4O* D92
{ <#ZDA/G(
e.printStackTrace (); A5q%ytI
} C<B1zgX
|M$ESj4@
w+Oo-AGNH
return n; {8im{]8_
} J_@`:l0,z
N*{>8iFo4
R64/m9
} 7nl
;=i$0w9W
-egu5#d>
/* VGL!)1b
**SiteInfoBean.java l(A>Rw|
*/ @FLa i
package NetFox; ];U}'&
JQO%-=t
) mG
public class SiteInfoBean { Xxmvg.Nl
OE8H |?%
^(.utO
private String sSiteURL; //Site's URL #- z(]Y,y
private String sFilePath; //Saved File's Path ;e#bl1%#
private String sFileName; //Saved File's Name no UXRQ
private int nSplitter; //Count of Splited Downloading File 8 aC]" C
qJ5gdID1_
*<IQ+oat,a
public SiteInfoBean() U66}nN9
{//nSplitter的缺省值为5 Y)KO*40c
//default value of nSplitter is 5 R1/87eB
this("","","",5); > Du>vlTY
} 'i7!"Y6>
?5Ub&{
c&>==pI]k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >XomjU[srQ
{ V+MhS3VD
sSiteURL= sURL; 1}DUe.a
sFilePath = sPath; >G<.^~o
sFileName = sName; ,].S~6IM
this.nSplitter = nSpiltter; 1v"r8=Wt
\*x=q20
=2tl149m/z
} uJ_"gPO
6~y7A<[^
w@Gk#
public String getSSiteURL() :d`8:gv?
{ KGq4tlM6
return sSiteURL; P6([[mmG
} 3^%sz!jK+
h8-'I=~
-_xC,dwK
public void setSSiteURL(String value) ;d{lvKk
{ h 1`yW#%
sSiteURL = value; t1%<l
} Q"QL#<N
_>)=c<HL
z;KUIWg
public String getSFilePath() v:w $l{7
{ =^D{ZZw{
return sFilePath; oEuo@\U05v
} /`YbHYNF[
8C4=f
O,A}p:Pgs
public void setSFilePath(String value) l0g`;BI_
{ Da WzQe=
sFilePath = value; /c9%|<O%
} 1WbawiG}
J"W+9sI0
J`@#yHL
public String getSFileName() R$xkcg2(
{ {V*OYYI`R
return sFileName; k w]m7T
} eHy.<VX
i<]Y0_?s
#&jr9RB
public void setSFileName(String value) 9'S~zG%{
{ 4t;m^Iv
sFileName = value; d;c<" +
} kn1+lF@
A_\ZY0Xt
sJ(q.FRM'
public int getNSplitter() A[.5Bi
{ ?=lnYDj
return nSplitter; ;N/=)m
} !s:v UY58
H%:u9DlEK/
<(<19t5.
public void setNSplitter(int nCount) fqgm`4>
{ 6opubI<
nSplitter = nCount; <0hJo=6a8
} uY5Gn.Y
} S.kFs{;1x
dPfDPb
N;BS;W5I
/* raPUx_$PH
**Utility.java 9&t!U+
*/ ;"@FLq(n
package NetFox; bk#t+tuk
D@yuldx'/
8*V8B=q}K
public class Utility { uVBMI.&w
l8_TeO
^"Nsb&
public Utility() 1q[vNP=g&
{ ;<yVJox
.$,.w__m~
m#oZu {
} I;!zZ.\
jt/ |u=
//线程睡眠 RL;>1Q,H
public static void sleep(int nSecond) _Di}={1[.
{ {lhdropd
try{ D|Tv`47ntu
Thread.sleep(nSecond); !"Q8KV
} `Y`QxU!d%
catch(Exception e) pdrF/U+
{ L'JEkji"
e.printStackTrace (); 7v~\c%1V
} F ;m1I+;
} I@f">&^
Cl+TjmOV\`
//日志 #VwA?$4g`
public static void log(String sMsg) q;kN+NK64
{ Wo^r#iRko
System.err.println(sMsg); vG<JOxP
} >iCkvQ
Qs*6wF
M!s@w%0?'
public static void log(int sMsg) rl,6ru
{ ]o(&J7Z6-
System.err.println(sMsg); zJfoU*G/B
} TZ7{cekQ
} t: =
"lp),
fi[c^e+IX
/* O_p:`h:;M
**TestMethod.java "DFj4XKXY9
*/ tN5brf
package NetFox; Rp2~d
FJN,er~T[
!0g+}
public class TestMethod { 9K8f ##3
Ge|& H]W
1{-W?n
public TestMethod() _cZ`7]Z
{ ///xx/weblogic60b2_win.exe s'V8PN+-
try{ :95wHmk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %rQ5 <U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $FgpFxz;
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z:#-4CiP
fileFetch.start(); C/Ig.KmXF{
} ({cgak
catch(Exception e){e.printStackTrace ();} "mAVkq~
N>OF tP
nFl=D=50-
} AcN~Q/xU
bl>MD8bzLE
Qr;es,f
public static void main(String[] args) "Yn<]Pa_
{ 62}bs/%
new TestMethod(); &Z+a (
} )>ed6A1
} [|2uu."$
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