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)); *cnxp-)ub
} v9K{oB
for(int i=0;i<nEndPos.length-1;i++) =zXii{t
{ f*Dy>sw
nEndPos = nStartPos[i+1]; gjnTG:}}}+
} {^qp~0
nEndPos[nEndPos.length-1] = nFileLength; ZQQ0}
} XexslzI
} b3RCsIz
8>y!=+9_
(hv>vfY@
//启动子线程 8wQ|Ep\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eX9Hwq4X44
for(int i=0;i<nStartPos.length;i++) BvA09lK
{ qe\JO'g#e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 95%, 8t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #0wH.\79
nStartPos,nEndPos,i); }|Wn6X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "/MA.zEl0,
fileSplitterFetch.start(); \L@DDK|"`6
} [O52Bn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _RcFV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "X7;^yY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ws>2S
nEndPos = " + nFileLength); vuCl(/P`
// fileSplitterFetch[nPos.length-1].start(); <.lT.>'?
?U;KwS]%
ozr82
//等待子线程结束 j~a"z40
//int count = 0; &/7D4!N]
//是否结束while循环 lIlmXjL0
boolean breakWhile = false; ?UPZ49y
n2#Yw}7^,o
vS$_H<;P
while(!bStop) =Hs[peO*
{ .h;PMY+
write_nPos(); ;HPQhN_
Utility.sleep(500); _poe{@h!
breakWhile = true; =Q!)xEK
=/b WS,=
T1&^IO-F7$
for(int i=0;i<nStartPos.length;i++) GvCB3z
{ .9Y,N&V<H
if(!fileSplitterFetch.bDownOver) U0Y;*_>4
{ zL<<`u?
breakWhile = false; \~:Uj~
break; lW!}OzE(m
} |QIFtdU5T
} #`>46T
if(breakWhile) B)bq@jM
break; HaUfTQ8
\ tK{!v+
mimJ_=]DC
//count++; wLDWD,"K
//if(count>4) LXm5f;
// siteStop(); ,>^6ztM
} b&l/)DU
Q--VZqn
,bQbj7
System.err.println("文件下载结束！"); Y}/e"mp
} NX?IM8\t
catch(Exception e){e.printStackTrace ();} z`^DQ8+\j
} u9:+^F+
bHi0N@W!vG
eoC@b/F4
//获得文件长度 !2R<T/9~
public long getFileSize() Jx:t(oUR+
{ 4a&*?=GG
int nFileLength = -1; /ox9m7Fz7
try{ qJQ!e
URL url = new URL(siteInfoBean.getSSiteURL()); nJvDkh#h1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !w!}`|q
httpConnection.setRequestProperty("User-Agent","NetFox"); 4r&S&^
/%#LA
oj6b33z
int responseCode=httpConnection.getResponseCode(); x tJ_azt
if(responseCode>=400) RcASFBNpS
{ ~1NK@=7T
processErrorCode(responseCode); *6-fvqCv
return -2; //-2 represent access is error p;GT[Ds^
} J< E"ZoY
[Ipg",Su;f
r@2{>j8
String sHeader; LxM.z1
6evW O!
HywT
for(int i=1;;i++) @wy&Z
{ C/JeD-JG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5,>Of~YN
//Utility.log(in.readLine()); w/L^w50pt
sHeader=httpConnection.getHeaderFieldKey(i); rcC}4mNe
if(sHeader!=null) 3H_mR j9th
{ >d`XR"_e
if(sHeader.equals("Content-Length")) nPW?DbH +
{ sg.8Sd"]7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +B 4&$z
break; Y7vTseq
} ,~R`@5+
} uN:|4/;{&
else pzo9?/-
break; >y2;sJ4]D%
} SNV[KdvP*
} uB(16|W>S
catch(IOException e){e.printStackTrace ();} x2#5"/~4
catch(Exception e){e.printStackTrace ();} arCi$:-z@
8sDbvVh1F
23lLoyN
Utility.log(nFileLength); r((2.,\Z
B@:c8}2.
+0w~Skd,
return nFileLength; d6$,iw@>^
} 14[+PoF^A
M~0A-*N
h6*&1r
//保存下载信息（文件指针位置） `A]CdgA
private void write_nPos() %uuh+@/&yz
{ yj^LX2x"
try{ -xJ_5
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~*3obZ2>2
output.writeInt(nStartPos.length); }Htnhom0n
for(int i=0;i<nStartPos.length;i++) |Ef\B]Ns
{ n21Pfig
// output.writeLong(nPos); A9*( O)
output.writeLong(fileSplitterFetch.nStartPos); [j6EzMN
output.writeLong(fileSplitterFetch.nEndPos); 4Y):d!'b
} W"m\|x
output.close(); A@8Ot-t:\2
} di@4'$5#
catch(IOException e){e.printStackTrace ();} r'kUU]j9
catch(Exception e){e.printStackTrace ();} cTA8F"UGD
} n{>Ge,enP0
D 8nt%vy
@}#"o
//读取保存的下载信息（文件指针位置） Q*S|SH-cZ0
private void read_nPos() w/8`]q
{ xbh4j!FD$
try{ l7 +#gPA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Di[}y;
int nCount = input.readInt(); ZZkxEq+D
nStartPos = new long[nCount]; bYuQ"K A$
nEndPos = new long[nCount]; 0_}^IiG
for(int i=0;i<nStartPos.length;i++) wq[\Fb`
{ [0_JS2KE
nStartPos = input.readLong(); `EV" /&`
nEndPos = input.readLong(); a@|/D\C
} R^}}-Dvr
input.close(); G}o?lo\#h
} L<kIzB !
catch(IOException e){e.printStackTrace ();} e&Z\hZBb
catch(Exception e){e.printStackTrace ();} T;cyU9
} ~R;9a"nr
AML8.wJ
jlmP1b9
private void processErrorCode(int nErrorCode) HT]v S}s
{ L53qQej<
System.err.println("Error Code : " + nErrorCode); Q^^.@FU"x
} \5+?wpH
k,EI+lCX
{U$qxC]M
//停止文件下载 v&6=(k{E@R
public void siteStop() hjuzVOE|W
{ _%HpB=
bStop = true; 81\$X
for(int i=0;i<nStartPos.length;i++) J{GtH[
fileSplitterFetch.splitterStop(); L{v^:
x.V6C0|6"
Cd4a7<-
} 4Xna}7
} IrJPP2Q
//负责部分文件的抓取 pUvbIbg+
**FileSplitterFetch.java Qg)=4(<Hr
*/ (nhv#&Fd+
package NetFox; G1;.\i
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b&LfL$
import java.io.*; G2FP|mf,
import java.net.*; U Ox$Xwp5&
-Jo8jE~>V
-IBf;"8f
public class FileSplitterFetch extends Thread { Sm(QgZO[4
9Fe(],AzF
? x1"uH
String sURL; //File URL (S:+#v
long nStartPos; //File Snippet Start Position traJub
long nEndPos; //File Snippet End Position oo{5:
int nThreadID; //Thread's ID F^5<o
boolean bDownOver = false; //Downing is over ;WQ@dC
boolean bStop = false; //Stop identical "J0,SFu:
FileAccessI fileAccessI = null; //File Access interface ; Q-f6)+&
fIrl?X']
aBPaC=g{HO
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yOn +Y
{ +/A`\9QT
this.sURL = sURL; | v? pS
this.nStartPos = nStart; DRldRm/
this.nEndPos = nEnd; j8@Eqh
nThreadID = id; l@+WGh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p_!;N^y.
} O<3i6
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%G%##wv:
public void run() *7"R[!9
{ > ,L'A;c}
while(nStartPos < nEndPos && !bStop) MC.,n$O}6
{ $}d| ~q\
Onr#p4UT
Da)rzr|}>3
try{ U D9&k^
URL url = new URL(sURL); NO4V{}?a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xl%!7?G|$>
httpConnection.setRequestProperty("User-Agent","NetFox"); s52c`+
String sProperty = "bytes="+nStartPos+"-"; x4SI TY
httpConnection.setRequestProperty("RANGE",sProperty); 39;Z+s";
Utility.log(sProperty); S- Mh0o"
xO2S|DH{
Mis t,H7
InputStream input = httpConnection.getInputStream(); 2#4_/5(j*
//logResponseHead(httpConnection); a8T<f/qW k
(fgX!G[W
O_*(:Z
byte[] b = new byte[1024]; )z0qKb\
int nRead; Ep%5wR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "ei*iUBN:
{ VjU;[
nStartPos += fileAccessI.write(b,0,nRead); RUTlwTdv
//if(nThreadID == 1) iSTr;>A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0G/VbS
} X!5
_m!TUT8o
!F0MLvdX7^
Utility.log("Thread " + nThreadID + " is over!"); /^~3Ib8Fw+
bDownOver = true; ,s'78Dc$
//nPos = fileAccessI.write (b,0,nRead); ,63hO.4M
} t&UPU&tY
catch(Exception e){e.printStackTrace ();} /#Y)nyE
} M.K-)r,
} !FweXFl
!1f8~"Z
hWK}] gF
//打印回应的头信息 cq'opjLf5
public void logResponseHead(HttpURLConnection con) JZp*"UzQr
{ kBY54pl
for(int i=1;;i++) zdCeOZ 6
{ _8C0z=hz
String header=con.getHeaderFieldKey(i); 1xM'5C?~7
if(header!=null) ?2VY^7N[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i^9PiP|U
Utility.log(header+" : "+con.getHeaderField(header)); &sL(|>N
else @;}bBHQz{p
break; ^(I4Do~}
} mrDIt4$D
} P&3'N~k-
96aA2s1
:>to?~Z1
public void splitterStop() dzZ74FE!t
{ BM*9d%m^
bStop = true; #LlHsY530N
} X>mY`$!/
P F!S
4l2i'H
} 6#XB'PR2p
ODK$G [-
Y:C7S~
/* OKfJ
**FileAccess.java 8~?3: IZ
*//文件访问(定位，写) 4 vwa/?
package NetFox; :mLcb.E
import java.io.*; C=ni5R
ua1ov7w$]
ud K)F$7
public class FileAccessI implements Serializable{ c0]^V>}cl
7N"$~UfC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d3h2$EDD
RandomAccessFile oSavedFile; v_f8zk
long nPos; gB@Xi*
"bAkS}(hB(
43pQFDWa
public FileAccessI() throws IOException <=8REA?
{ 6k;__@B,
this("",0); *vFVXJo
} FblwQ-D
/_E8'qlx
LZm6\x
public FileAccessI(String sName,long nPos) throws IOException @sJ[<V
{ Pw/Z;N;:V
oSavedFile = new RandomAccessFile(sName,"rw"); +MPM^m
this.nPos = nPos; g\&[;v i
oSavedFile.seek(nPos); m"\jEfjO
} > 4ex:Z
b7g\wnV8z
yfeX=h
public synchronized int write(byte[] b,int nStart,int nLen) )n 1b
{ Ddde,WJA
int n = -1; Z<ozANbk
try{ oK&LYlU
oSavedFile.write(b,nStart,nLen); j<>|Hi #`
n = nLen; ^,')1r,
} 24"Trg\WK[
catch(IOException e) O[f*!
{ Ed,`1+
e.printStackTrace (); zu&5[XL
} ZzLmsTtzIu
$8o(_8Q)
\|nF55W [
return n; ]kq{9b';
} a'f"Zdh%w
. $uvQpyh
o^;$-O!/
} 6H67$?jMyJ
<jF]SN
cc7*O
/* ^D\1F$AjC
**SiteInfoBean.java xc[@lr
*/ YLVV9(
package NetFox; 9tsI1]1[m
4k_&Q?1
zQ9"i
public class SiteInfoBean { $j:$ `
$u_0"sUV
!Uz{dFJf;
private String sSiteURL; //Site's URL 3}=r.\]U
private String sFilePath; //Saved File's Path L^} Z:I
private String sFileName; //Saved File's Name 0F-X.Dq
private int nSplitter; //Count of Splited Downloading File 1C\OL!@L
D_ xPa
!TY9\8JzV
public SiteInfoBean() |t*(]U2O0
{//nSplitter的缺省值为5 t m?[0@<s
//default value of nSplitter is 5 n"8vlNeW
this("","","",5); IY6DZP
} 24PEt%2
c^vPd]Ed
\"B?'Ep;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7l> |G,[c
{ D].!u{##
sSiteURL= sURL; T:q_1W?h]
sFilePath = sPath; ~4h<nc
sFileName = sName; Wr Ht
this.nSplitter = nSpiltter; BDSZ'
){`s&?M0
:b)IDcW&j:
} HQ~`ha.
%JM:4G|q
$ysemDq-a\
public String getSSiteURL() `Bk7W]{L
{ R06L4,/b
return sSiteURL; )I'?]p<
} C( 8i0(1
W[BZ/
5vs~8|aRo
public void setSSiteURL(String value) nf&PDv1
{ ;q]Jm
sSiteURL = value; B*7Y5_N
} xgHR;USH
vN:gu\^-
\"Z^{Y[,;
public String getSFilePath() \7PPFKS
{ Q\Dx/?g!vx
return sFilePath; r!SMF]?SJ
} ^Gt&c_gH
lxb+0fiN
e5G)83[=
public void setSFilePath(String value) yG\^PD
{ wqB{cr}!
sFilePath = value; 0fwmQ'lW(
} q/U(j&8W{
n&ZArJ
r(;oDdVc
public String getSFileName() nVkx Q?2
{ jGpSECs
return sFileName; C(zgBk
} |f), dC
|U{9Yy6p
F: %-x=q
public void setSFileName(String value) l?pF?({
{ lM1~K
sFileName = value; O O?e8OU
} FsQeyh>
{y)O?9q
MCOiB<L6
public int getNSplitter() Z`x|\jI
{ /jl{~R#1
return nSplitter; ]&6# {I-
} HS>(y2}'
!/]F.0
8*7t1$
public void setNSplitter(int nCount) .4on7<-a
{ <=.0 P/N
nSplitter = nCount; Pyh+HD\
} \7rAQ[\#V
} .nN=M>#/
4x7(50hp#
6. N?=R
/* "fK`F/
**Utility.java YXCltME
*/ sd4eJ
package NetFox; X`#,*HkK
oSVo~F
@>`+eg][?P
public class Utility { <vMna< /d
K$v SdpC
rEz-\jLD~
public Utility() +8qtFog$\g
{ o6`4y^Q{/
c%1k'Q
@}[>*Xy%
} Mx9#YJ?t~
PWeCk2xH
//线程睡眠 sF9{(Us
public static void sleep(int nSecond) W0e+yIaR
{ ,b[}22
try{ $!Z><&^/
Thread.sleep(nSecond); l{b<rUh5W
} s18o,Zs'
catch(Exception e) lGrp^
{ fH#yJd2?f
e.printStackTrace (); :QKxpHi
} wEju`0#;
} vByt_X
=&+]>g{T
//日志 337y,;
public static void log(String sMsg) eC%uu
{ =5:L#` .
System.err.println(sMsg); 4I7B #{
} \s_lB~"P!3
rJLn=|uR
3V=(P.ATm
public static void log(int sMsg) aq~>$CHa
{ c:#<g/-{wM
System.err.println(sMsg); b#ga
} bVfFhfh*
} e^v5ai
UN ;9h9
&O|!w&
/* -CV_yySc
**TestMethod.java hxG=g6:G
*/ V|6PKED
package NetFox; +'fy%/
wVegr
0|6]ps4Z7
public class TestMethod { ~K'e}<-G
`O~NT'Ed8
LV4\zd6
public TestMethod() k+-IuO
{ ///xx/weblogic60b2_win.exe mCM7FFl I
try{ b1+6I_u.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'iQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &d,chb(
SiteFileFetch fileFetch = new SiteFileFetch(bean); sk'<K5~
fileFetch.start(); m7<HK,d
} dA,irb I0W
catch(Exception e){e.printStackTrace ();} %>,B1nt
Q?"o.T';
IZ){xI
} 99QMMup
!LGnh
ku2gFO
public static void main(String[] args) s|40v@M
{ cnJL*{H<2
new TestMethod(); '5^$v{
} g/*x;d=
} m(2(Caz{
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