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)); 3*b5V<}'|
} w:~*wv
for(int i=0;i<nEndPos.length-1;i++) HgI!q<)
{ x]~TGzS
nEndPos = nStartPos[i+1]; w0pMH p'Y
} $XBK_ 5
nEndPos[nEndPos.length-1] = nFileLength; ?^}30V:E
} TCtZ2 <'
} qNp1<QO0
c'2d+*[
r"h;JC/&<T
//启动子线程 I=Y>z^4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JxAQ,oOO
for(int i=0;i<nStartPos.length;i++) jlEz]@ i
{ @mp`C}x"0&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B/? L$m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bOS)vt*V
nStartPos,nEndPos,i); 4M'>oa
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?$r`T]>`2
fileSplitterFetch.start(); .])prp8
} E-e(K8R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7R+(3NU1A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AOf4y&B>q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hsZ/Vnn`
nEndPos = " + nFileLength); ,Kit@`P%
// fileSplitterFetch[nPos.length-1].start(); ]I*c:(qwu
9>""xt
2ZH+fV?.
//等待子线程结束 XR5KJl
//int count = 0; D:)Wr, 26
//是否结束while循环 KWTV!Wxb=K
boolean breakWhile = false; H=r-f@EOrI
y4V:)@P
Z6jEj9?O
while(!bStop) enoj4g7em^
{ D7Q+w
write_nPos(); &y[NCAeA
Utility.sleep(500); iyskADS
breakWhile = true; hy;VvAH5
f)I5=Ijy(
boh?Xt-$
for(int i=0;i<nStartPos.length;i++) {4"V)9o-1>
{ =;}W)V|X)S
if(!fileSplitterFetch.bDownOver) kc,"w\ ai
{ GkIE;7#2kX
breakWhile = false; B.z$0=b
break; &W `xZyb3
} bOY;IB _
} "4j~2{{F
if(breakWhile) %H{p&ms
break; "fFSZ@,r
[oWkd_dK
%!|w(Povq
//count++; i`,FXF)
//if(count>4) _k-_&PR
// siteStop(); VYyija:
} f60w%
V\~.
H=dIZ
System.err.println("文件下载结束！"); OvdT* g=8*
} $ /VQsb
catch(Exception e){e.printStackTrace ();} .nV2n@SR
} 5*0zI\
$KHm5*;nd
3"fDFR
//获得文件长度 JJ.8V72;!Z
public long getFileSize() b*|~F
{ Bous d
int nFileLength = -1; Ts iJK
try{ *4,Q9K_
URL url = new URL(siteInfoBean.getSSiteURL()); Vns3859$8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]5!3|UYS
httpConnection.setRequestProperty("User-Agent","NetFox"); [K{{P|(q
[m~J6WB
>A#5` $i
int responseCode=httpConnection.getResponseCode(); 6W1GvM\e
if(responseCode>=400) Z9{~t
{ 3G})$y3m
processErrorCode(responseCode); Z:4/lx7Bq
return -2; //-2 represent access is error ZR.k'
} sEhvx+(
8f@}-
~/OY1~c
String sHeader; R|;BO:S1
n.%QWhUB
;p`1Y<d-O
for(int i=1;;i++) =j7Du[?Vu
{ bzN[*X|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V&mkS
//Utility.log(in.readLine()); M!&Hn,22
sHeader=httpConnection.getHeaderFieldKey(i); 0b&#w
if(sHeader!=null) W"{Ggk`
{ rxCzPF
if(sHeader.equals("Content-Length")) *yq65yZi5
{ js$R^P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }1a}pm2p
break; GT{4L]C
} q'D Ts9Bj
} Y;'<u\^M"
else m^X51,+<
break; x#{!hL 5G
} >hunV'vu'
} emSq{A
catch(IOException e){e.printStackTrace ();} Y@,iDQ
catch(Exception e){e.printStackTrace ();} 6?Ncgj &@
hBgE%#`s
!gh8 Qs
Utility.log(nFileLength); >%/x~UFc5
Q%e<0t7
zJQh~)
return nFileLength; \JLGw1F
} YQ0#j'}/
|)x7qy`
IjI'Hx
//保存下载信息（文件指针位置） y-<.l=6A
private void write_nPos() $8^Hkxy
{ *l5?_tF
try{ 7x)Pt@c
output = new DataOutputStream(new FileOutputStream(tmpFile)); *'@Oo
output.writeInt(nStartPos.length); =Rd`"]Mnfb
for(int i=0;i<nStartPos.length;i++) 7q0_lEh
{ xGs}hVlZiC
// output.writeLong(nPos); OqtGKda
output.writeLong(fileSplitterFetch.nStartPos); _i_='dsyW/
output.writeLong(fileSplitterFetch.nEndPos); 91OxUVd
} ;"dX]":
output.close(); s5~k]"{j
} ^'3c%&Zf3
catch(IOException e){e.printStackTrace ();} =\Q<TY
catch(Exception e){e.printStackTrace ();} "vGh/sXW
} <rC%$tr
G,C`+1$*
gL<n?FG4b
//读取保存的下载信息（文件指针位置） OP/DWf
private void read_nPos() IQ&PPC
{ _8G w Mj
try{ RELNWr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >u=
int nCount = input.readInt(); aoy Be|H~=
nStartPos = new long[nCount]; i{$-[*WHiV
nEndPos = new long[nCount]; a (U52dO,
for(int i=0;i<nStartPos.length;i++) _k:8ib2TQ
{ pg{VKrT`
nStartPos = input.readLong(); 6Bq_<3P_
nEndPos = input.readLong(); fHiL%]z
} h)Y] L#R
input.close(); BX_yC=S
} 9NTNulD>P
catch(IOException e){e.printStackTrace ();} =3-=p&*
catch(Exception e){e.printStackTrace ();} fcq8aW/z_
} v3"6'.f;bY
nJI2IPZ
JrcbJt
private void processErrorCode(int nErrorCode) o~$O$
{ ]>M\|,wh
System.err.println("Error Code : " + nErrorCode); Nu7>G
} /&Q{B f
/r4l7K
} =OE.cf@
//停止文件下载 xPZ>vCg
public void siteStop() V$ZclV2:Ih
{ )<5k+O~
bStop = true; q,Gymh;
for(int i=0;i<nStartPos.length;i++) <::lfPP
fileSplitterFetch.splitterStop(); Zn9tG:V
Pd7\Q]of
^ ]9K>}
} ZLjAhd)
} 7y$\|WG?!r
//负责部分文件的抓取 n])#<0
**FileSplitterFetch.java }y6)d.
*/ K]|UdNo
package NetFox; ||hQ*X<m>
"$(+M t^
J>(X0@eWz
import java.io.*; ~| j eNT
import java.net.*; ` <1Wf
y#'hOSR2
6f +aGz
public class FileSplitterFetch extends Thread { C8K2F5c5
Z3]I^i FI
L/"MRQ"
String sURL; //File URL ^+x?@$rq
long nStartPos; //File Snippet Start Position >!Yuef <P
long nEndPos; //File Snippet End Position F*P0=DD
int nThreadID; //Thread's ID ,D{7=mDVm
boolean bDownOver = false; //Downing is over mG S4W;
boolean bStop = false; //Stop identical -;9 }P
FileAccessI fileAccessI = null; //File Access interface 7}&:07U
AJ7w_'u=@
oz&`3`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,4'gj0
{ ?Ek)" l
this.sURL = sURL; ~ *&\5rPb
this.nStartPos = nStart; dJR[9T_OF
this.nEndPos = nEnd; u ON(LavB
nThreadID = id; ZR!8hw8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [rx9gOOa&
} '?C6P5fm
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-,")GA+[7
public void run() necY/&Ld-
{ -+ByK#<%
while(nStartPos < nEndPos && !bStop) |<Ls;:5.
{ -m@c{&r
!R8%C!=a
}StzhV{GS
try{ kk78*s {6
URL url = new URL(sURL); n%3!)/$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S"!6]!~^
httpConnection.setRequestProperty("User-Agent","NetFox"); 4AJ]qu
String sProperty = "bytes="+nStartPos+"-"; _^FC9
httpConnection.setRequestProperty("RANGE",sProperty); 3%*igpj\)
Utility.log(sProperty); jf3Zy:*K
[-\Y?3
\dHqCQ
InputStream input = httpConnection.getInputStream(); Q:q0C +T
//logResponseHead(httpConnection); r(r(&NU
k>ErDv8
UPH#~D!
byte[] b = new byte[1024]; hJM&rM7
int nRead; htB7 j(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b d 1^
{ g}%ODa !H
nStartPos += fileAccessI.write(b,0,nRead); x;[ .ZzQ
//if(nThreadID == 1) Ovt]3`U9J
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3A,N1OXG
} Lip#uuuXXN
+Q+O$-a<
o"JHB
Utility.log("Thread " + nThreadID + " is over!"); 1]If< <
bDownOver = true; xVPSL#>
//nPos = fileAccessI.write (b,0,nRead); LtB5;ByeQ0
} M@TG7M7Os
catch(Exception e){e.printStackTrace ();} qlcd[Y*B
} 9(]_so24,
} Fizrsr 6%
QD.5oS
LGL;3EI
//打印回应的头信息 04U|Frc
public void logResponseHead(HttpURLConnection con) 2xN7lfu1RB
{ 5x@U<
for(int i=1;;i++) 7=fM}sk
{ 4(\1z6?D
String header=con.getHeaderFieldKey(i); 3.YH7rN
if(header!=null) L9/'zhiZBx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U,2OofLM
Utility.log(header+" : "+con.getHeaderField(header)); #)S}z+I
else `:lcN0n
break; a >fA-@
} cPtDIc,
} 1le9YL1_g
|6d:k~p
eSoX|2g
public void splitterStop() TU?n;h#TZ
{ EG\L]fmD
bStop = true; aKMX-?%t4
} q<\r}1Dm
:(enaHn#~
Kj?)]Z4
} IG0_
w8D8\`i!"
.:H'9QJg
/* Vc'p+e|(
**FileAccess.java ;s3@(OnjZ
*//文件访问(定位，写) u&p8S#e
package NetFox; gS(JgN
import java.io.*; pjO
=pe O%
<;i&-,
public class FileAccessI implements Serializable{ "Io-%Su+
(a!E3y5,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]Q^8 9?
RandomAccessFile oSavedFile; 'NWvQR<X
long nPos; Ew}GPJ
@uC-dXA"
h%:wIkZ/
public FileAccessI() throws IOException gu3)HCZ
{ iP7KM*ks
this("",0); 9^SrOW6~
} fo}@B&=4
Ct/6<
MS SHMR
public FileAccessI(String sName,long nPos) throws IOException >VjtKSN
{ m$Tt y[0
oSavedFile = new RandomAccessFile(sName,"rw"); ]Gl_L7u`
this.nPos = nPos; i_6wD
oSavedFile.seek(nPos); ICoZ<;p
} 9LQy0Gx
7({.kD6
kH=~2rwm
public synchronized int write(byte[] b,int nStart,int nLen) w*SFQ_6YE
{ b(ryk./ogx
int n = -1; /9y'UKl7[
try{ fv3)#>Dgp>
oSavedFile.write(b,nStart,nLen); 7Ph+Vs+h
n = nLen; x^F2Ywp%
} nDC5/xB
catch(IOException e) p|Fhh\,*`X
{ ZG)C#I1;O
e.printStackTrace (); /=OSGIJzm
} 9]8M{L
_Q;M$.[zyR
uP ?gGo
return n; 4d'tK^X
} 8<^6<c
^?[^o\/@R
r3{o_w
} B<'V7#L_
&sA6o"h~
1[`l`Truz
/* e;}5~dSi
**SiteInfoBean.java H"?-&>V-
*/ f{Y|FjPp=E
package NetFox; u= +
+XRv iHA`
e]X9"sd0=
public class SiteInfoBean { zZh`go02E
XWy iS\
XY QUU0R
private String sSiteURL; //Site's URL qV$',U*+T
private String sFilePath; //Saved File's Path z06pX$Q.<
private String sFileName; //Saved File's Name +Vf|YLbhJ
private int nSplitter; //Count of Splited Downloading File d`nS0Tf'
0_y%Qj^e
cwC,VYVl
public SiteInfoBean() s3kEux^
{//nSplitter的缺省值为5 $ .Z2Rdlv(
//default value of nSplitter is 5 +`Bn]e8O
this("","","",5); ]R>k0X.V
} ?h3Ow`1G
D3lYy>~d5;
".i{WyTt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `Zi#rr|)L
{ FfgJ 2y
sSiteURL= sURL; -MEz`7c~
sFilePath = sPath; +@qk=]3a
sFileName = sName; mVL,J=2
this.nSplitter = nSpiltter; yEqmB4^-
tr/dd&(Y1
aQmL=9
} 835Upj>
NU(/Yit
,]{NZ9
public String getSSiteURL() 9f6TFdUi"y
{ _~(Xd@c(
return sSiteURL; E\*",MGL
} # |I@`#O
G([vy#p
bv4cw#5z$9
public void setSSiteURL(String value) !Cy2>6v7
{ RZtL<2.@
sSiteURL = value; XfrnM^oty
} %UJ4wm
a*[\edcHU
wf@2&vJ
public String getSFilePath() YcV~S#b
{ ncdr/(`
return sFilePath; FOA%(5$4
} E\S&} K,s
Madaxx
r*wKYb
public void setSFilePath(String value) RHbp:Mlk
{ UIj/Id
sFilePath = value; ~QcKW<bz
} (B-9M)
$bosGG
lpUtNy
public String getSFileName() ;LE @Ezx
{ j2Y(Q/i
return sFileName; ix+x-G
} ACYn87tq
}aM`Jp-O
3@?YTez#
public void setSFileName(String value) \AzcW;03g[
{ \W^+vuD8
sFileName = value; .A/H+.H;
} 2QRn c"
Dg+d=I?
eBIR*TZ):
public int getNSplitter() odf^W
{ Z|%2495\
return nSplitter; ji -1yX
} kG$8E
F:S>\wG,
\=_q{
public void setNSplitter(int nCount) /*^|5>-`i1
{ 4"x;XVNM[
nSplitter = nCount; 1T,PC?vr{
} oD@jtd>b%
} H<}eoU.
y?#J`o- O
_lv:"/3R
/* ,GU/l)os`
**Utility.java eI rmD
*/ _C,@eu"9V
package NetFox; ]=VS~azZ5
"ak9LZQ9z
E0^%|Mh]b
public class Utility { 0uO=wOIhH
%`1CE\f
>-5Gt
public Utility() #x@lZ!Y
{ <Iyot]E
33'lZubV
G? gXK W
} xTFrrmxOf
F*JvpI[7n
//线程睡眠 ]Bd3d%
public static void sleep(int nSecond) _s^:zPl
{ 2, "q_d'V
try{ oXlxPN39
Thread.sleep(nSecond); 9_WPWFO
} oA;Ty7s
catch(Exception e) k;_KKvQ
{ 6$fnQcpJ
e.printStackTrace (); t_>bTcsU
} ;s\;78`0
} Qj<{oZp&
UcLNMn|
//日志 f./m7TZ
public static void log(String sMsg) yaRcBT?
{ xPDA475Cw3
System.err.println(sMsg); PL9eUy
} 5u|=;Hz*)
Uy59zB2|=
H8-D'q>R
public static void log(int sMsg) wL-ydMIx
{ De nt?
System.err.println(sMsg); !q$&JZY
} :\+{;;a@
} 0i*'N ch#i
nRXSW&V"m
{;iHYr-zs
/* juCG?}di;
**TestMethod.java _iGU|$a
*/ G=C5T(
package NetFox; cNuHXaWp
@Xve qUUU
%]chL.s
public class TestMethod { Foe>}6~{?
%[Zqr;~l
%9QMzz5
public TestMethod() `&u<aLA
{ ///xx/weblogic60b2_win.exe rmPne8D=c(
try{ A-a17}fta
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `y^zM/Ib
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *bCi2mbm@
SiteFileFetch fileFetch = new SiteFileFetch(bean); s-C!uq
fileFetch.start(); C{UF~
} b8N[."~:
catch(Exception e){e.printStackTrace ();} |oe!P}u
<H5n>3#pH
GSz @rDGY
} DO&+=o`"
YVB% kKv{
;.ysCF
public static void main(String[] args) 5c:'>
{ r]k*7PK
new TestMethod(); jDlA<1
} GA|/7[I}
} ^oQekga\l
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