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)); 6xmZXpd!
} *uRBzO}
for(int i=0;i<nEndPos.length-1;i++) ](]i 'fE>
{ 20h} [Q(
nEndPos = nStartPos[i+1]; h%na>G
} C\3rJy(VJ
nEndPos[nEndPos.length-1] = nFileLength; T3.&R#1M8-
} {_"<1C
} IxN9&xa
;3coP{
wD}l$& +
//启动子线程 & bm 1Fz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .bl/*s
for(int i=0;i<nStartPos.length;i++) +zN-!5x
{ RZ?jJm$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G^|:N[>B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9 RgVK{F
nStartPos,nEndPos,i); VR8-&N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r| wS<cA2
fileSplitterFetch.start(); np^N8$i:n
} z]y.W`i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kPG-hD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %g$o/A$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vkV0On
nEndPos = " + nFileLength); ?3`UbN:
// fileSplitterFetch[nPos.length-1].start(); 'W^YM@
U[-o> W#
)T2Caqs2
//等待子线程结束 =U9*'EFr
//int count = 0; 9!\B6=r y4
//是否结束while循环 "Qc7dRmSxm
boolean breakWhile = false; yjX9oxhtL
B)g[3gQ
.p3,O6y2(F
while(!bStop) e\l7Iu
{ >Eto( y"q
write_nPos(); :6 R\OeH+
Utility.sleep(500); CNyIQ}NJ
breakWhile = true; '3fu
N/2T[s_&
+.[ <%
for(int i=0;i<nStartPos.length;i++) nPl?K:(
{ =z69e%.
if(!fileSplitterFetch.bDownOver) BhGu!Y6f
{ pofie$
breakWhile = false; u'DRN,h+
break; sY Qk
} :U%W%
} VA_PvL.9
if(breakWhile) ^"2J]&x`G
break; mR:uj2*
/nNN,hz
*)T^ChD,
//count++; HCs?iJ
//if(count>4) WPMSm<[
// siteStop(); `?_Q5lp/s
} !)0;&e5
'Aq{UGN
zKJ#`OhT
System.err.println("文件下载结束！"); ChPmX+.i_
} )~JHgl
catch(Exception e){e.printStackTrace ();} cf20.F{<
} f+,qNvBY/
3$>1FoSk
)yZ^[uJ}3C
//获得文件长度 /]Md~=yNp
public long getFileSize() | rtD.,m
{ dOH&
int nFileLength = -1; :>f )g
try{ 6}Ci>_i4#
URL url = new URL(siteInfoBean.getSSiteURL()); BG]#o|KW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f+)L#>Gl?
httpConnection.setRequestProperty("User-Agent","NetFox"); WO>nIo5Y
s8t;.^1}
u^I|T.w<r6
int responseCode=httpConnection.getResponseCode(); 8^1 Te m
if(responseCode>=400) 08\,<9
{ V5>B])yQ
processErrorCode(responseCode); Flm%T-Dl
return -2; //-2 represent access is error Vv=. -&'
} ]Q3ADh
21l;\W
#r\4sVg
String sHeader; wE`]7mA
Moza".fiN
wc4{)qDE
for(int i=1;;i++) HBXOjr<,{
{ SZ'R59Ee<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w;amZgD>
//Utility.log(in.readLine()); Wt-GjxGi
sHeader=httpConnection.getHeaderFieldKey(i); Z=o2H Bm7
if(sHeader!=null) ?1 4{J]H4
{ j6 z^Tt12
if(sHeader.equals("Content-Length")) /7F:T[
{ kxhWq:[c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +\ .Lp 5
break; &B1WtW
} e6$WQd`O
} r[iflBP
else SoK iE
break; VjZ|$k
} 4vB<fPN
} Eo]xNn/g
catch(IOException e){e.printStackTrace ();} @lrztM
catch(Exception e){e.printStackTrace ();} 7~.9=I'A
Dp-z[]})1
/@TF5]Ri
Utility.log(nFileLength); @`- 4G2IU}
z<XtS[ki
>U27];}y
return nFileLength; m~0/&RA
} HY:o+ciH'
6mxfLlZ
Z,Dl` w
//保存下载信息（文件指针位置） (gWm,fI RZ
private void write_nPos() GH$pKB
{ e=m42vIB-
try{ Q sCheHP
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^o&. fQ*
output.writeInt(nStartPos.length); G3AesTT|
for(int i=0;i<nStartPos.length;i++) JOeeU8C
{ M&9+6e'-F
// output.writeLong(nPos); Ne1$ee.NE
output.writeLong(fileSplitterFetch.nStartPos); PIS2Ed]
output.writeLong(fileSplitterFetch.nEndPos); F0Yd@Lk$_
} '3^'B03
output.close(); |#R7wnE[k~
} $suzW;{#
catch(IOException e){e.printStackTrace ();} T%*D~=fQ'
catch(Exception e){e.printStackTrace ();} }y gD3:vN7
} w@w(-F!%l
t&e{_|i#+
.V8Lauz8
//读取保存的下载信息（文件指针位置） )|#sfHv7
private void read_nPos() &`2)V;t
{ )oPBa
try{ di )L[<$DY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JYHl,HH#z
int nCount = input.readInt(); U9MxI%tb
nStartPos = new long[nCount]; q9s=~d7
nEndPos = new long[nCount]; d<P\&!R(
for(int i=0;i<nStartPos.length;i++) p9{mS7R9T
{ O)r4?<Q
nStartPos = input.readLong(); Z=vU}S>r|v
nEndPos = input.readLong(); !%%6dB@%t
} IF:;`r@%
input.close(); i?^L/b`H
} R~q]JSIC@
catch(IOException e){e.printStackTrace ();} g{&ui.ml&
catch(Exception e){e.printStackTrace ();} 'E""amIJ
} >}6%#CAf
{&1/V
[S!/E4>['
private void processErrorCode(int nErrorCode) \(2sW^fY
{ Q>Yjy!.<^
System.err.println("Error Code : " + nErrorCode); Wg]Qlw`\|
} "S?z@i(K^
{F.[&/A
w ;^ra<*<+
//停止文件下载 t;\Y{`
public void siteStop() &gx%b*;`L0
{ A^<jy=F&
bStop = true; YT(AUS5n
for(int i=0;i<nStartPos.length;i++) h(EhkCf
fileSplitterFetch.splitterStop(); *(DV\.l`
P\k# >}}
o!A+&{
} cSV aI
} SO0PF|{\r
//负责部分文件的抓取 #S"nF@
**FileSplitterFetch.java v`1M[
*/ @E|}Y
package NetFox; H9e<v4c
}&D32\
1]b.fD
import java.io.*; -nV9:opD
import java.net.*; P/_['7
o?\?@H
O:Tj"@h
public class FileSplitterFetch extends Thread { [d]9Oa4
d7bS wL
EXqE~afm2
String sURL; //File URL S30%)<W
long nStartPos; //File Snippet Start Position qUb&
long nEndPos; //File Snippet End Position 7-fb.V9
int nThreadID; //Thread's ID kE1TP]|
boolean bDownOver = false; //Downing is over `VguQl_,gA
boolean bStop = false; //Stop identical ?%[jR=w
FileAccessI fileAccessI = null; //File Access interface aK^q_ghh[
X#^[<5
;9QEK]@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6(-N FnT
{ YPI-<vM~
this.sURL = sURL; Cq~dp/V
this.nStartPos = nStart; .8JTe0
this.nEndPos = nEnd; Ml-6OvQ7g
nThreadID = id; U|R_OLWAg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sK?twg;D*|
} inp7K41
/Lr.e%
NC6&x=!3
public void run() PLBrP
{ (X*^dO
while(nStartPos < nEndPos && !bStop) \1M4Dl5!
{ gL/9/b4
Z6MO^_m2
vKAN@HSYr
try{ &s>Jb?_5Mx
URL url = new URL(sURL); h^P#{W!e\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tw)mepwB
httpConnection.setRequestProperty("User-Agent","NetFox"); XfIJ4ZM5
String sProperty = "bytes="+nStartPos+"-"; cQ}{[YO
httpConnection.setRequestProperty("RANGE",sProperty); uHRsFlw
Utility.log(sProperty); S~G]~gt
&m;*<}X
lNO;O}8
InputStream input = httpConnection.getInputStream(); w7&A0M
//logResponseHead(httpConnection); +R75v)
&_8947
{R{=+2K!|k
byte[] b = new byte[1024]; _ jlRlt
int nRead; 9H1rO8k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gbD KE{
{ H3oFORh
nStartPos += fileAccessI.write(b,0,nRead); lPAQ3t!,
//if(nThreadID == 1) -yNlyHv9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cPQiUU~W@
} \a3+rNdj
Y8t8!{ytg
es0hm2HT3
Utility.log("Thread " + nThreadID + " is over!"); [{/jI\?v
bDownOver = true; n~Lt\K:
//nPos = fileAccessI.write (b,0,nRead); E=O\0!F|b
} ?+8\.a!
catch(Exception e){e.printStackTrace ();} %A0/1{(
} 1Ai^cf:S
} 1G`Pmh@
3o/[t
dqcL]e
//打印回应的头信息 8H`[*|{'
public void logResponseHead(HttpURLConnection con) `kSZX:=};
{ iH'p>s5L
for(int i=1;;i++) ,<X9Y2B
{ -trkA'ewZ
String header=con.getHeaderFieldKey(i); 05^h"
if(header!=null) y8xE 6i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0PCGDLk8
Utility.log(header+" : "+con.getHeaderField(header)); b7ZSPXV
else 'Z]w^<
break; ue>D7\8
} 2B`JGFcdcB
} iU:cW=W|M\
K@%].:
TkF[x%o
public void splitterStop() z0Z%m@
{ ]I6 J7A[
bStop = true; Zb#u0Tq
} Rk8P ax/JK
c+GG\:gM
qxJ\ye+'*
} .A|@?p[
wKY_Bo/d
{\\Tgs
/* og>uj>H&
**FileAccess.java 0IWf!Sk ]
*//文件访问(定位，写) MUwMb!Z.s
package NetFox; &6k3*dq
import java.io.*; .eC1qWZJpd
DIUjn;>k8
;9'OOz|+1
public class FileAccessI implements Serializable{ /<BI46B\
nT)vNWT=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ht&YC<X
RandomAccessFile oSavedFile; {7pli{`
long nPos; 9Gz=lc[!7
HLi%%"'
tZB<on<.)
public FileAccessI() throws IOException uvS)8-o&F
{ e8b:)"R
this("",0); a-J.B.A$Z/
} _Bj":rzY
]J]h#ZHx
Z5]>pJFq,
public FileAccessI(String sName,long nPos) throws IOException /_ajaz%
{ |sZHUf_
oSavedFile = new RandomAccessFile(sName,"rw"); >c}u>]D
this.nPos = nPos; yEQs:v6L~
oSavedFile.seek(nPos); mXs; b 2r^
} ,"79P/C
h!9ei6
@9|hMo
public synchronized int write(byte[] b,int nStart,int nLen) J9S>yLQK
{ <ZR9GlIr
int n = -1; % %UE+u@J
try{ Wh{tZ~c
oSavedFile.write(b,nStart,nLen); cQ_Hp <D
n = nLen; Q=yg8CQ
} C+&l< fM&
catch(IOException e) ]')RMg zM*
{ ^T-V^^#(
e.printStackTrace (); ?=pT7M
} 7"D.L-H
iO; 7t@]-
8DaL,bi*.
return n; 'H<\x
} Wo=jskBrQ
X)3!_
, ++ `=o
} 0_t!T'jr7
Uf+%W;}
` sU/& P
/* $L]lHji
**SiteInfoBean.java 7Hu3>4<
*/ 8}| (0mC
package NetFox; 5l*&>C[(i
iOO)Q\
wLr_-vJ
public class SiteInfoBean { q> C'BIr
65^9
45>?o
private String sSiteURL; //Site's URL /&94 eC
private String sFilePath; //Saved File's Path #Mw8^FST
private String sFileName; //Saved File's Name i~J'%a<Qp
private int nSplitter; //Count of Splited Downloading File ]OzUGXxo~
12LL48bi
A^<iL
public SiteInfoBean() um0N)&iY
{//nSplitter的缺省值为5 M=r)I~
//default value of nSplitter is 5 J7p),[>I<
this("","","",5); XpJ7o=?W3
} CeC6hGR5
G'A R`"F
XOS[No~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I2 P@L?h
{ _5N]B|cO
sSiteURL= sURL; S^\Vgi(
sFilePath = sPath; n7-6- #
sFileName = sName; :6\qpex
this.nSplitter = nSpiltter; @I!0-OjL
emN*l]N
JFk lUgg
} B0]~el
&KRX[2
`+Q%oj#FF
public String getSSiteURL() (JFWna0@
{ y_lU=(%Jd
return sSiteURL; TbW38\>.R
} U\*J9
!d0kV,F:
I&W=Q[m
public void setSSiteURL(String value) $ gS>FJ
{ ~FG]wNgS
sSiteURL = value; ut7zVp<"
} 81 sG
fS78>*K
j+ 0I-p
public String getSFilePath() oEZdd#*;
{ +!.^zp21
return sFilePath; Qn)a/w-
} YglmX"fLf
vnZC,J `
ZX./P0
public void setSFilePath(String value) 5taT5?n2
{ 1NA.nw.
sFilePath = value; L>4"(
} VQ9/Gxdeo
&Ys<@M7E:
CN8Y\<Ar
public String getSFileName() fHd#u%63K
{ 57']#j#"hj
return sFileName; |imM#wF
} #fn)k1
fSvM(3Y<Qh
K:#I
public void setSFileName(String value) _TQj~W<
{ VY=jc~c]v
sFileName = value; Ig0VW)@
} Gm^U;u}=f
3eAX.z`D
EDl!w:
public int getNSplitter() ,w:U#r~s"
{ eiaFaYe\
return nSplitter; rlSeu5X6
} L2i_X@/
uGK.\PB$
!@*7e:l
public void setNSplitter(int nCount) #r~# I}U
{ X[BIA+6
nSplitter = nCount; ~H<6gN<j(.
} Gk&)08
} hT&Y#fh
ZdWm:(nkU
w4{<n/"
/* :vQrOn18p
**Utility.java Q6!zZ))~
*/ By",rD- r
package NetFox; A>;bHf@
?(F6#"/E
sW'AjI
public class Utility { Nv}=L : E
Q%f^)HZGR
X Dm[Gc>(~
public Utility() a;qryUyG
{ ND#Yenye
hPkWCoQpq
b;W3j
} Ru!iR#s)!
S8wLmd>
//线程睡眠 JWhdMU
public static void sleep(int nSecond) dI@(<R
{ l<LP&
try{ G kl71VX
Thread.sleep(nSecond); (Ag16
} D4lG[qb
catch(Exception e) }mYx_=+VX
{ [")o.(
e.printStackTrace (); 8f)?{AX0
} TA`1U;c{n
} IS{wtuA.
$=8 NED5
//日志 M4oy
public static void log(String sMsg) 2W96Zju\
{ +_?hK{Ib"
System.err.println(sMsg); t?x<g<PJ4
} F|o:W75
7{)G_?Q&
RXpw!
public static void log(int sMsg) 9N%We|L,c
{ 0d"[l@UU0
System.err.println(sMsg); qo90t{|c
} u<6<iD3y
} *8yAG]z
<EB+1GFuI
-aPg#ub
/* (cAIvgI
**TestMethod.java _"Dv uR
*/ j^j1
package NetFox; 3nIU1e
@;zl
\Xt7`I<
public class TestMethod { 6y%qVx#!
L3u&/Tn2
2\A$6N;_
public TestMethod() 53;}Nt#R
{ ///xx/weblogic60b2_win.exe N=T<_`$5
try{ rxgbV.tx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $<dH?%!7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W+aP}rZm:
SiteFileFetch fileFetch = new SiteFileFetch(bean); G\/zkrxmv
fileFetch.start(); F 5bj=mI
} ITE{@1
catch(Exception e){e.printStackTrace ();} knu,"<
6"LcJ%o
a?I= !js
} v}}F,c(f
[64:4/<}
!=*g@mgF
public static void main(String[] args) i^X]j
{ GfxZ'VIn
new TestMethod(); *)$Uvw E
} APn|\
} #vz7y(v
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