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^#Sb
} i $I|JJJ
for(int i=0;i<nEndPos.length-1;i++) :-"J)^V
{ sWavxh8A
nEndPos = nStartPos[i+1]; ziH2<@
} MqoQs{x
nEndPos[nEndPos.length-1] = nFileLength; E=QL4*?
} m\Tq0cT$
} $d8A_CUU
&g& &-=7)
4`8.\
//启动子线程 ?sS'T7r v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -S,dG|
for(int i=0;i<nStartPos.length;i++) ]LSa(7>EU
{ hq,;H40%/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [tD*\\IA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iBo-ANnK9
nStartPos,nEndPos,i); 5\4>H6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o~4n8
fileSplitterFetch.start(); !zJ.rYZ=g`
} ~-:CN(U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rM=Hd/ki5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {eZj[*P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #[KwR\b{:+
nEndPos = " + nFileLength); ok6e=c '
// fileSplitterFetch[nPos.length-1].start(); :T{or-
8dA/dMQ
GrQl3 Xi
//等待子线程结束 8V|-BP5^
//int count = 0; zfo.S[R@
//是否结束while循环 <M&]*|q>g%
boolean breakWhile = false; n/|/Womr
epG;=\f}m`
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while(!bStop) ^U`q1Pg5
{ <=7)t.
write_nPos(); ~IqT>
Utility.sleep(500); s lI)"+6
breakWhile = true; &pba~X.u
rSJ}qRXwU
=VY4y]V
for(int i=0;i<nStartPos.length;i++) {VNeh
{ Aj`4uFhiL
if(!fileSplitterFetch.bDownOver) C|lMXp\*
{ AQV3ZVP
breakWhile = false; ncA2en?
break; y]CJOC)/K
} M^[jA](a
} nb|MHtPX
if(breakWhile) `nM4kt7
break; hy]AH)?pR
fZ376Z:S$
0[i]PgIH
//count++; ]Aluk|"`U
//if(count>4) z::2O/ho
// siteStop(); C=b5[, UCB
} C {,d4KG
(i?^g &
(,TO|
System.err.println("文件下载结束！"); f7W=x6Z4
} 3PEs$m9e
catch(Exception e){e.printStackTrace ();} *AA1e}R{B
} #rC/y0niH
\bsm#vY,
vOj$-A--qU
//获得文件长度 d{trO;%#f
public long getFileSize() dog,vUu
{ 7,4x7!
int nFileLength = -1; :_H88/?RR
try{ *&PgDAQ
URL url = new URL(siteInfoBean.getSSiteURL()); UetmO`qju
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zSH#j RDV
httpConnection.setRequestProperty("User-Agent","NetFox"); x!jhWX
Lf:Z (Z>
b7,qzh
int responseCode=httpConnection.getResponseCode(); a;zcAeX
if(responseCode>=400) avz 4&
{ 8`~]9ej
processErrorCode(responseCode); Tc*PDt0C
return -2; //-2 represent access is error k^]~NP
} ;i:7E#@
' #mC4\<W8
,-"]IR!,w
String sHeader; }*t~&l0
cs5Xd
lm\u(3_$
for(int i=1;;i++) 19vD(KC<
{ 4<Y?#bm'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gf=*m"5
//Utility.log(in.readLine()); Pn#Lymxh_a
sHeader=httpConnection.getHeaderFieldKey(i); QezK&iJg
if(sHeader!=null) ?l(hS\N,
{ Q4PXC$u
if(sHeader.equals("Content-Length")) Cf N; `
{ <>Im$N ai
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &Xav$6+Z1J
break; Ll`apKr
} $d=lDN
} 5eLPn
else 5 9vGLN!L
break; # 9t/j`{
} FdqUv%(Em
} 8xX{y#
catch(IOException e){e.printStackTrace ();} HHYcFoJwYN
catch(Exception e){e.printStackTrace ();} Kv7NCpq'
O?!"15
pDLo`F}A
Utility.log(nFileLength); @RP|?Xc{?
smU+:~
z)B=<4r
return nFileLength; >gE_?%a[
} 'nno)kQ"
x,%&[6(
Qi61(lK
//保存下载信息（文件指针位置） 3C2>
private void write_nPos() [ZbK)L+_
{ &)l:m.
try{ i&$uG[&P
output = new DataOutputStream(new FileOutputStream(tmpFile)); #o RUH8
output.writeInt(nStartPos.length); ;D1IhDC
for(int i=0;i<nStartPos.length;i++) +\%zy=
{ f/x "yUq
// output.writeLong(nPos); 1 W u
output.writeLong(fileSplitterFetch.nStartPos); SMyg=B\x?7
output.writeLong(fileSplitterFetch.nEndPos); 1dcy+ !>
} 2&m7pcls
output.close(); L7-nPH
} nM`)`!/
catch(IOException e){e.printStackTrace ();} -ZB"Yg$l
catch(Exception e){e.printStackTrace ();} Exr7vL
} "->:6Oe2
B(falmXJ
||V:',#,W
//读取保存的下载信息（文件指针位置） X3[!xMij
private void read_nPos() :dzU]pk%0
{ +0 MKh
try{ Sx2j~(pOr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hqPn~Tq
int nCount = input.readInt(); q*OKA5
nStartPos = new long[nCount]; g$b*#
nEndPos = new long[nCount]; .IXwa,
for(int i=0;i<nStartPos.length;i++) pA'A<|)K0
{ 4_<Uk
nStartPos = input.readLong(); * 5n:+Tw(
nEndPos = input.readLong(); qpl5n'qHUc
} p2G8Qls
input.close(); Ub,unU
} "}! rM6 h
catch(IOException e){e.printStackTrace ();} {76!
catch(Exception e){e.printStackTrace ();} R=PzR;8
} ^ne8~ ;Q
7,TWCVap
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private void processErrorCode(int nErrorCode) jGn^<T\
{ Qx;A; n!lw
System.err.println("Error Code : " + nErrorCode); 7o. 'F
} 3U)8P6Fz
}El_.@'T &
!U_L7
//停止文件下载 cy4'q?r
public void siteStop() Pc'?p
{ &pm{7nH
bStop = true; `qTY
for(int i=0;i<nStartPos.length;i++) TeJ `sJ
fileSplitterFetch.splitterStop(); iC]lO
w>uZ$/
OX4D'
} )*ckJK
} B! V{.p
//负责部分文件的抓取 Q\L5ZJ%y/
**FileSplitterFetch.java Br5Io=/wg
*/ ak`)>
package NetFox; gf?^yP ;V
wVDB?gy%#
: qRT9n$
import java.io.*; keskD
import java.net.*; NrcCUZ .:N
@'@6vC
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public class FileSplitterFetch extends Thread { Tm\[q
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dH|^\IQ
String sURL; //File URL e-9unnk
long nStartPos; //File Snippet Start Position x[UO1% _o-
long nEndPos; //File Snippet End Position <q2nZI^
int nThreadID; //Thread's ID <R>z;2c
boolean bDownOver = false; //Downing is over 070IBAk}_
boolean bStop = false; //Stop identical *K'ej4"u
FileAccessI fileAccessI = null; //File Access interface P*`xiTA
/Ph&:n\4
"Q{~Bj~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4/?}xD|?
{ 1 ],, Ar5
this.sURL = sURL; 4Z9wzQ>
this.nStartPos = nStart; ~+C?][T
this.nEndPos = nEnd; 8"mW!M
nThreadID = id; f<Tz#w&6W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a +yI2s4Z
} !m(L0YH
;bZ*6-\!-
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public void run() vN:[
{ )C]&ui~1
while(nStartPos < nEndPos && !bStop) *Ne&SXg
{ ROS"VV<
g ypq`F
[P=[hj;
try{ o!`O i5
URL url = new URL(sURL); ^85n9a?8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8zDH<Gb
httpConnection.setRequestProperty("User-Agent","NetFox"); {$YD-bqY
String sProperty = "bytes="+nStartPos+"-"; x ;,xd
httpConnection.setRequestProperty("RANGE",sProperty); FLI8r:
Utility.log(sProperty); v9m;vWp
+\GZ(!~
WwtE=od
InputStream input = httpConnection.getInputStream(); yr2L
//logResponseHead(httpConnection); 2BX GVo
f&|A[i>g
QhQ"OVFr#
byte[] b = new byte[1024]; !]+Z%ed`%
int nRead; 5!jNL~M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6F.7Ws<
{ 6h6?BQSE
nStartPos += fileAccessI.write(b,0,nRead); wZ8 MhE
//if(nThreadID == 1) .*-w UBr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B36puz 0{
} OP`Jc$|6
'z}M[h K]
e ]o'i;I
Utility.log("Thread " + nThreadID + " is over!"); =yX&p:-&
bDownOver = true; igBrmaY'
//nPos = fileAccessI.write (b,0,nRead); o 7W Kh=
} 4:&qTY)H
catch(Exception e){e.printStackTrace ();} #z!Hb&Qi\
} RB7AI!'a?
} yISQYvSN
)|y2Q
L'XdX\5
//打印回应的头信息 |F@xwfgb
public void logResponseHead(HttpURLConnection con) xX/s1(P
{ IAF;mv}'
for(int i=1;;i++) Secq^#]8
{ M'zS7=F!:
String header=con.getHeaderFieldKey(i); 5 k%9>U%$
if(header!=null) S=H_9io
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =lC;^&D-0/
Utility.log(header+" : "+con.getHeaderField(header)); hMeqs+
else w zqd g
break; 1i/::4=
} nt0\q'&
} )R8%'X;U
#3K,V8(
$.Q>M]xH
public void splitterStop() R G0S
{ Afy .3T @)
bStop = true; VkDS&g~Ws
} (y~laW!
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!3I(4?G,
} daB l%a=
mPfUJ#rS
1%spzkE 3P
/* 6UW:l|}4#2
**FileAccess.java 9Ue7 ~"=
*//文件访问(定位，写) S2&9#6
package NetFox; %8bzs?QI
import java.io.*; +an^e'
^{*f3m/
)nNCB=YF!
public class FileAccessI implements Serializable{ z_Wm HB
Yn4)Zhkk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,<$YVXe/
RandomAccessFile oSavedFile; n{^<&GWox
long nPos; (7;J"2M
q11QAx4p
uKbHFF
public FileAccessI() throws IOException @q+cmJKv
{ j&dx[4|m:h
this("",0); * {gxI<
} J0Hm)*
) \-96 xd
cophAP
public FileAccessI(String sName,long nPos) throws IOException G(As%r]
{ GG_^K#*
oSavedFile = new RandomAccessFile(sName,"rw"); ,v*p
this.nPos = nPos; *Mwfod
oSavedFile.seek(nPos); #dZ/UM(u
} M'umoZmW0
QJ#u[hsMFp
&nqdl+|G*
public synchronized int write(byte[] b,int nStart,int nLen) uNe}"hs
{ qDRNtFa
int n = -1; \D,M2vC~G
try{ )X~Pr?52?
oSavedFile.write(b,nStart,nLen); =a)iVXSB]
n = nLen; Gefnk!;;
} _Z+jQFKJ\8
catch(IOException e) \Pl,' 1%
{ hdd>&?p3
e.printStackTrace (); }XCR+uAz
} S5~`T7Ra
,!6M*|
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return n; ImWXzg3@{
} EO#gUv
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d7"U WY^
} Ecxj9h,S
{sC@N![
T-9k<,>?
/* |N:MZ#};
**SiteInfoBean.java dD/t_ {h
*/ {*QvC g?
package NetFox; T?X^0UdJj
$%g\YdC
%Kh2E2Pe
public class SiteInfoBean { pi`;I*f/
~`t%M?l
qyg*n>nt
private String sSiteURL; //Site's URL atY*8I|
private String sFilePath; //Saved File's Path K??1,I
private String sFileName; //Saved File's Name ~ HK1X
private int nSplitter; //Count of Splited Downloading File ]alh_U
[_WI8~gY
g4N%PV8
public SiteInfoBean() jHAWK9fa
{//nSplitter的缺省值为5 s$DGd T)
//default value of nSplitter is 5 i2$*}Cu
this("","","",5); NW{y%Z
} 6Z~Ya\~.g.
.zvlRt.zl
f.||PH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LthGZ|>
{ Dd| "iA
sSiteURL= sURL; +0]'| tF>
sFilePath = sPath; g<fDY6jt
sFileName = sName; WP5VcBC
this.nSplitter = nSpiltter; `Kh]x9Z
tM&n3MWQ
\n#]%X5c
} Hqvc7-c6
QU:EY'2
pT4qPta,2
public String getSSiteURL() Ptx,2e&Hq
{ [%)@|^hw91
return sSiteURL; * [tc
} 6|,e%
i90}Xyt
@l'G[jN5
public void setSSiteURL(String value) bE?'C h
{ UqN{JG:#.
sSiteURL = value; 0$tjNye
} qAqoZMpI|;
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\e<mSR
public String getSFilePath() T^~)jpkw
{ <eY%sFq,
return sFilePath; 75ZH
} B&?fM~J
H+a~o=/cR
k({2yc#RD&
public void setSFilePath(String value) q(IZJGb
{ m}98bw
sFilePath = value; rFo\+//
} }sv!=^}BY3
h40'@u^W
a mqOxb
public String getSFileName() CWs: l3_yn
{ ;)?( 2 wP
return sFileName; BDy5J2<<7l
} tQrS3Hz'nA
.`,F
Uo2+:p
public void setSFileName(String value) Vvyj
{ MM#i t=u
sFileName = value; mzGjRl=O
} 1?(cmXj
*(G&B\
ahA{B1M)n
public int getNSplitter() 7{pIPmJ
{ 7rcA[)<'
return nSplitter; ^ Hg/P8q
} eIg+PuQD]
f])M04<
NPm;
public void setNSplitter(int nCount) f ba&`
{ T"?Y5t`(
nSplitter = nCount; jv =EheD
} !EOQhh
} .s2$al
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o@9+mM"B)
/* g:_hj_1Y M
**Utility.java ;1 |x
*/ ~^&R#4J
package NetFox; II;Te7~
~.Cv DJy
f2yq8/J8.
public class Utility { 9_ZBV{
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,}0$Tv\1
public Utility() ]]TqP{H
{ xvmt.>f
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%X>FVlPm
} gO='A(Y
WULAty
//线程睡眠 =A@>I0(7
public static void sleep(int nSecond) qZ*f%L(
{ ~U$":~H[
try{ )JhT1j Qc
Thread.sleep(nSecond); -#.< 12M
} d yh<pX/$
catch(Exception e) :g2 }C
{ (wuaxo:
e.printStackTrace (); 7?J3ci\
} byGn,m
} qsI^oBD"
QXVC\@
//日志 nBz`q+V
public static void log(String sMsg) +j{Y,t{4
{ eY,O@'"8`
System.err.println(sMsg); BLn_u,3
} $.rzc]s
R,t$"bOd
M0L&~p_F
public static void log(int sMsg) %2"J:0j
{ |sIr?RL{C
System.err.println(sMsg); c~imE%
} PLA#!$c7q
} _c2WqQ-05
`G!M>h@
j*400
/* *fnvZw?
**TestMethod.java $dQIs:
*/ mR%FqaN_
package NetFox; }D*yr3b
T\9~<"P^
:,S98z#
public class TestMethod { z.oU4c
.[:VSM7T
8{0k0 &x
public TestMethod() W:`#% :C
{ ///xx/weblogic60b2_win.exe @gY\;[#.
try{ tY+$$GSQj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hmC*^"C>U=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lnh+a7a)
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'yY>as
fileFetch.start(); '<dgT&8C
} R)5n 8
catch(Exception e){e.printStackTrace ();} .Z\Q4x#!Z
YoKs:e2/:
$q_R?Eay
} %m&@o~+
"OmD@ EMT
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public static void main(String[] args) )Si2u5
{ Ps4 ZFX
new TestMethod(); wN=;i#
} S($Su7g%_
} 0 1V^L}
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