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)); D>b5Uwt
} auTTvJ
for(int i=0;i<nEndPos.length-1;i++) 'Rd*X6dv
{ f H|QAMfOu
nEndPos = nStartPos[i+1]; <!}l~Ln15
} i(yAmo9h
nEndPos[nEndPos.length-1] = nFileLength; L\wpS1L(
} J7wQ=!g
} Dnm.!L8
9_WPWFO
fb.\V]K
//启动子线程 Xu94v{u3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DwY<qNWT
for(int i=0;i<nStartPos.length;i++) X0Z-1bs
{ wEnuUC4j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =ch Af=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WCmNibj
nStartPos,nEndPos,i); m_!vIUOz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jp3di&x
fileSplitterFetch.start(); Qj<{oZp&
} YG 5Z8@kH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lAn+gDP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q|= Q]$d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .d~]e2x
nEndPos = " + nFileLength); V l~Y
// fileSplitterFetch[nPos.length-1].start(); C7 ]DJn
d9-mWz(V+
k/_8!^:'
//等待子线程结束 |[owNV>
//int count = 0; 2@R8P~^W
//是否结束while循环 fQW_YQsb
boolean breakWhile = false; P A6KX5
CI!Eq&D,
N`<4:v[P
while(!bStop) H/Ec^Lc+_
{ Bq~hV;9nf
write_nPos(); |v$%V#Bo
Utility.sleep(500); \YlF>{LVe
breakWhile = true; UhSh(E8p>
71l"m^Z3zy
5Hwo)S]r
for(int i=0;i<nStartPos.length;i++) VqClM
{ Uc&6=5~Ys\
if(!fileSplitterFetch.bDownOver) D,dHP-v
{ :qAc= IC%
breakWhile = false; =l8!VJa
break; _iGU|$a
} fEj9R@u+h
} cNuHXaWp
if(breakWhile) jKj=#O
break; S0N2rU
(lN;xT`=
p<HTJ0
//count++; NDRW
//if(count>4) 9'n))%CZ.
// siteStop(); xi?P(sA
} ^$=tcoQG
:J Gl>V
'n^2|"$sH
System.err.println("文件下载结束！"); ;v,9v;T
} 1c)\
catch(Exception e){e.printStackTrace ();} %Ui{=920
} \m=-8KpU
A \MfF
8 )mjy!,
//获得文件长度 -7I1Lh#M
public long getFileSize() #ox9&
{ q}<.x8\
int nFileLength = -1; 1iNsX\M
try{ ha|@ Xp
URL url = new URL(siteInfoBean.getSSiteURL()); C{UF~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PG6[lHmi
httpConnection.setRequestProperty("User-Agent","NetFox"); X(GmiH /E
Mhe|eD#)
(!ZQ
int responseCode=httpConnection.getResponseCode(); rb:<N%*t
if(responseCode>=400) 1KTabj/C
{ |jahpji6
processErrorCode(responseCode); a{]g+tGH
return -2; //-2 represent access is error l_c^ .D
} *?_qE
`E} p77
<$jKy3@
String sHeader; r"{Is?yKe
6kt]`H`cfJ
\}$*}gW[}
for(int i=1;;i++) i1qS ns
{ Jo{zy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~~C6)N~1
//Utility.log(in.readLine()); 0).fBBNG
sHeader=httpConnection.getHeaderFieldKey(i); T!l mO?Q
if(sHeader!=null) i>Z|65
{ Lw>-7)
if(sHeader.equals("Content-Length")) F8{ldzh
{ VLcyPM@"Q!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0LWdJ($?
break; F+ffl^BQ
} 81g9ZV(4
} Ro'jM0(KE
else g!1I21M1~
break; \f(Y:}9
} C(-[ Y!
} aGPqh,<QD
catch(IOException e){e.printStackTrace ();} Q0V^PDF
catch(Exception e){e.printStackTrace ();} Z0e-W:&;kF
O6yP qG*j
2BHKS-J*
Utility.log(nFileLength); W1xf2=z`)T
EfKM*;A
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return nFileLength; 1^aykrnQ>
} ;"1/#CY773
&&X$d!V
L~*u4
//保存下载信息（文件指针位置） 9[z'/U.Bn
private void write_nPos() /@&(P#h
{ r2RBrZ@1
try{ n}19?K]g
output = new DataOutputStream(new FileOutputStream(tmpFile)); P?^JPbfV
output.writeInt(nStartPos.length); mT96]V\
for(int i=0;i<nStartPos.length;i++) AK6=Ydu
{ B ,V(LTE
// output.writeLong(nPos); <u0*"
output.writeLong(fileSplitterFetch.nStartPos); 8)N0S% B
output.writeLong(fileSplitterFetch.nEndPos); c#=&!FRe
} X(IyvfC
output.close(); D899gGe
} 43KaL(
catch(IOException e){e.printStackTrace ();} FyCBNtCv
catch(Exception e){e.printStackTrace ();} e\`wlaP,
} z~F37]W3[
p` $fTgm
Jf2e<?`
//读取保存的下载信息（文件指针位置） mv{<'
private void read_nPos() !?jK1{E3
{ +<&E3Or
try{ jQ6Xr&}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ze&#i6S
int nCount = input.readInt(); pg+b[7
nStartPos = new long[nCount]; 5`"iq "5Cf
nEndPos = new long[nCount]; Qe_+r(3)k
for(int i=0;i<nStartPos.length;i++) 2zhn`m
{ ^[#=L4
nStartPos = input.readLong(); fTBVvY4(
nEndPos = input.readLong(); k!&:(]
} Z%#^xCz;w>
input.close(); jDkm:X}:
} {t&*>ma6)
catch(IOException e){e.printStackTrace ();} d [r-k 2
catch(Exception e){e.printStackTrace ();} J<rlz5':
} OZ=Cp$
f_rp<R>Uu
VrVDm*AGQ
private void processErrorCode(int nErrorCode) @a0Q0M
{ ?b56AE
System.err.println("Error Code : " + nErrorCode); p+$+MeBz
} &Y+e=1a+
6F(hY !}5
wZQ)jo7*g
//停止文件下载 guU=NQZ
public void siteStop() $(3uOsy
{ #G[t X6gU
bStop = true; ^+wk
for(int i=0;i<nStartPos.length;i++) 40u7fojg2
fileSplitterFetch.splitterStop(); CI^[I\$&
\0nlPXk?G
})PO7:
} mg`j[<wp
} tU{\ev$x
//负责部分文件的抓取 ;=a_B1"9u
**FileSplitterFetch.java B[CA 5Ry
*/ 44~hw:
package NetFox; F_ 81l<
U9 bWU'
33 :@*
import java.io.*; okstY4f'
import java.net.*; p-xd k|'[
D^|9/qm$
w//omF'`
public class FileSplitterFetch extends Thread { yPoSJzC=[
afx'
4@h;5
String sURL; //File URL gX^ PSsp
long nStartPos; //File Snippet Start Position %&h c"7/k
long nEndPos; //File Snippet End Position myIe_k,F
int nThreadID; //Thread's ID W&YU^&`Yr
boolean bDownOver = false; //Downing is over _lX8K:C(
boolean bStop = false; //Stop identical V#L'7">VP
FileAccessI fileAccessI = null; //File Access interface zW5C1:.3K
*GJ:+U&m[
b!^@PIX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U7h(-dV
{ a~opE!|m
this.sURL = sURL; w^Ag]HZN
this.nStartPos = nStart; &<Zdyf?[Ou
this.nEndPos = nEnd; 8eN7VT eb
nThreadID = id; FAw1o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hO \/
} s1bU
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public void run() R5(F)abi
{ LTXz$Z]
while(nStartPos < nEndPos && !bStop) bY)#v?
{ 45<y{8
Zj!Abji=O
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try{ 2 x32U MD
URL url = new URL(sURL); e>AXXUEf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |@wyC0k!
httpConnection.setRequestProperty("User-Agent","NetFox"); f@d9Hqr+l;
String sProperty = "bytes="+nStartPos+"-"; yQ%"U^.m
httpConnection.setRequestProperty("RANGE",sProperty); Us=eq "eu
Utility.log(sProperty); `eR 7H>I
Om9jtWk
!),t"Ae?>
InputStream input = httpConnection.getInputStream(); to`mnp9Z
//logResponseHead(httpConnection); RgZOt[!.
Hhl-E:"H`
+D`*\d1
byte[] b = new byte[1024]; MA* :<l
int nRead; -ihiG_f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .T8K-<R
{ N=~~EtX
nStartPos += fileAccessI.write(b,0,nRead); 2+Yb 7 uI,
//if(nThreadID == 1) e<"/'Ql!k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wd+K`I/v7h
} I 8zG~L%"
0` 5e
I2[]A,f,
Utility.log("Thread " + nThreadID + " is over!"); '3Q3lM'lh
bDownOver = true; R\O.e
//nPos = fileAccessI.write (b,0,nRead); )];aIA$
} tJ'iX>9I
catch(Exception e){e.printStackTrace ();} snC/H G7
} FnE6?~xa
} wk @,wOt
[_.n$p-
24B<[lSK
//打印回应的头信息 iKAusWj
public void logResponseHead(HttpURLConnection con) 3i=Iu0
{ |8U;m:AS
for(int i=1;;i++) B<,YPS8w
{ qINTCm j
String header=con.getHeaderFieldKey(i); izuF !9
if(header!=null) /{*$JF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Qihdn66
Utility.log(header+" : "+con.getHeaderField(header)); VteEDL/w
else #{PmNx%M
break; ^$NJD
} 6R4<J%$P
} ^R~~L
Q2QY* A
f~ U.a.Fb
public void splitterStop() e|lD:_1i
{ s&Yi 6:J
bStop = true; 8ObeiVXf)
} f^b K=#
^sClz*%?
N$#\Xdo
} iqPBsIW
'*T]fND4
#*^+F?o,(
/* 5-vo0:hk
**FileAccess.java "pvH0"Q*
*//文件访问(定位，写) #g9ZX16}
package NetFox; OZ(dpV9.S
import java.io.*; @Rq}nq=k
]?K. S6
Z :nbZHByh
public class FileAccessI implements Serializable{ $k%Z$NSN=
s([dGD$i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sWqM?2g
RandomAccessFile oSavedFile; -d=WV:G%e
long nPos; >*1}1~uU`'
qTmD'2
,hRN\Kt)p
public FileAccessI() throws IOException $>q@SJ1q
{ 1cC1*c0Z
this("",0); c0rk<V%5+
} m9":{JI.w
Im?LIgt$
#b)e4vwCq
public FileAccessI(String sName,long nPos) throws IOException 7~UR!T9
{ 'i|rjW(
oSavedFile = new RandomAccessFile(sName,"rw"); eV};9VJ$F
this.nPos = nPos; .*5Z"Q['G
oSavedFile.seek(nPos); >)**khuP7
} ELD!{bMT
JAjku6
\ |!\V
public synchronized int write(byte[] b,int nStart,int nLen) K$[$4 dX]
{ U[\Vj_?(I
int n = -1; z5 m>H;P
try{ wkb$^mU
oSavedFile.write(b,nStart,nLen); J/x2qQ$9
n = nLen; N4!<Xj
} [f{VIE*?%
catch(IOException e) 4. qtp`
{ i$^ZTb^
e.printStackTrace (); k%81f'H
} V5mTu)tp5
(6gK4__}]
)"<8K}%!
return n; :d,^I@]
} ajH"Jy3A
N#z~
cP>o+-)
} m$2<`C=
q1{H~VSn"
.*/Fucr
/* nk=$B(h
**SiteInfoBean.java \2e0|)aF6
*/ zGlZ!t:
package NetFox; L}k/9F.5
K_&MoyJJ9f
j`>^1Q
public class SiteInfoBean { [iS$JG-
-ysn&d\rV
7jG(<!,
private String sSiteURL; //Site's URL ROb\Rxm
private String sFilePath; //Saved File's Path 19U]2D/z
private String sFileName; //Saved File's Name !{%:qQiA
private int nSplitter; //Count of Splited Downloading File $jzFc!rs
hZ$t$3
dp5cDF}l
public SiteInfoBean() ku&k'V
{//nSplitter的缺省值为5 ``K#}3
//default value of nSplitter is 5 Xyx"A(v^l
this("","","",5); ~Ci{3j :]
} iz[gHB
^+|De}`u
| A)\ :
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b^CNVdo'
{ L"(4R^]
sSiteURL= sURL; {]N3f[w
sFilePath = sPath; D-p.kA3MJ
sFileName = sName; 5Rv+zQ#GR
this.nSplitter = nSpiltter; N"7]R[*
t0E51Ic@
0\QR!*'$
} nms8@[4-
QG gF|c7
A;X=bj _&a
public String getSSiteURL() 45 >XKr.%
{ chI.{Rj
return sSiteURL; :$r ^_
} YA]5~ZE\
KLWDo%%u
0Q9T3X
public void setSSiteURL(String value) )xU-;z0"~
{ Q[4: xkU
sSiteURL = value; fxQN+6;
} $iw%(H
%yS3&Ju
3251Vq %
public String getSFilePath() H*I4xT@
{ G;iEo4\?
return sFilePath; y'C-[nk
} Tny>D0Z#
Z}6^ve
R W/z1
public void setSFilePath(String value) xyh.N)
{ S=|@L<O
sFilePath = value; L@Nu/(pB=
} LRb,VD:/Y
4_?7&G0(
'fd1Pj9~$
public String getSFileName() {p<Zbm.
{ ()T[$.(
return sFileName; G=9d&N
} a:STQk V
|AZW9
io2)1cE&f
public void setSFileName(String value) R!\EKH
{ .p` pG3
sFileName = value; u'~;Y.@i'
} 5`+5{p
~%k?L4%
~p1EF;4#
public int getNSplitter() uzr\oj+>
{ k=ytuV\
return nSplitter; S::=85[>z
} \E1U@6a
,L> ar)B
QCOo
public void setNSplitter(int nCount) ^rNUAj9Z
{ p*QKK@C
nSplitter = nCount; <[ Xw)/#
} A#wEuX=[
} I3b"|%
3INI?y}t
xl9aV\W
/* K,ej%Vtz
**Utility.java sy* y\5yJ
*/ YNdrWBf)
package NetFox; uzOYVN$t
Dh|w^Q
qQ[b VD\*
public class Utility { 3Hi+Z}8
],etZ%z&
C)-^<
public Utility() \*vHB`.,ey
{ Nh?|RE0t
\*T"M*;
OR6ML-|
} {lG@hN'
E$s/]wnr[
//线程睡眠 <i?a0
public static void sleep(int nSecond) ^Mkk@F&1
{ `TqSQg_l
try{ Qq& W3
Thread.sleep(nSecond); w0m^ &,;#
} z`Wt%tL(
catch(Exception e) :fcM:w&
{ c,EBF\r8*
e.printStackTrace (); \/`?
} =JLh?Wx
} x+5k <Xi}
SUCUP<G
//日志 9Ru;`
public static void log(String sMsg) imB#Eo4eY
{ Nil}js27
System.err.println(sMsg); d;[u8t
} M5L{*>4|6
R{Z-m2La
kK>Xrj6
public static void log(int sMsg) |iYg >
{ zSTR^sgJ
System.err.println(sMsg); qeL pXe0c
} ,*id'=S
} F'8T;J7
>T3H qYX5W
&Nl2sey
/* \5 pu|2u
**TestMethod.java Fe&qwq"
*/ \p&~,%
package NetFox; B1 0+*p(
#^#Kcg
[onqNp
public class TestMethod { BbOu/i|
or*HC&c7
=v~1qWX
public TestMethod() AnsjmR:Jv
{ ///xx/weblogic60b2_win.exe _;9!
try{ Xt/Ksw"wn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8kL4~(hY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bKVj[r8D~
SiteFileFetch fileFetch = new SiteFileFetch(bean); %y[1H5)3<
fileFetch.start(); A?!I/|E^;
} 7Ey#u4Q
catch(Exception e){e.printStackTrace ();} !eR3@%4
S0/usC[r
$P o}
} k_|^kdWJ
-cF'2Sfr
~,6b_W p/
public static void main(String[] args) 5AeQQU
{ sd re#@n}
new TestMethod(); \t4tiCw
} Z,7R;,qX
} H[Q_hY[>V
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