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)); &eCa0s?mI
} )4<__|52"1
for(int i=0;i<nEndPos.length-1;i++) $JJrSwR<h
{ $Q96,rb}k;
nEndPos = nStartPos[i+1]; HkUWehVm
} c#Sa]n
nEndPos[nEndPos.length-1] = nFileLength; q_g+Jf P-D
} El[)?+;D
} +;N2p1ZBf
VEqS;~[
bF"G[pD
//启动子线程 %,6#2X nX%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %|g>%D3Z?
for(int i=0;i<nStartPos.length;i++) TDFkxB>
{ #h8Sq~0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zF8dKFE~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :Q $K<)[
nStartPos,nEndPos,i); q Gw -tPD<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Qip&IN
fileSplitterFetch.start(); 5_I->-<
} nrxo&9[@n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `\gnl'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ma.`A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [E!oQVY
nEndPos = " + nFileLength); K9$>Yxe|
// fileSplitterFetch[nPos.length-1].start(); \?0&0;5
Tx|Ir+f6L
9`I _Et
//等待子线程结束 +*ZO&yJQ^<
//int count = 0; w+#C-&z
//是否结束while循环 a(kg/s
boolean breakWhile = false; 6:Ch^c+IZ
]>LhkA@V
Z&1T
while(!bStop) ysxb?6
{ 8\^}~s$$A
write_nPos(); V5sg#|&
Utility.sleep(500); FT#8L
breakWhile = true; u37'~&o{U
4C<jdv_J
JJ}0gZ
for(int i=0;i<nStartPos.length;i++) Rot@x r7Hc
{ kP#B5K_U|
if(!fileSplitterFetch.bDownOver) h]+C.Eqnt#
{ Ne8Cgp
breakWhile = false; M dZ&A}S
break; Tl$[4heE
} - }7e:!.
} 8jd;JPz@\
if(breakWhile) ZHU5SXu
break; [ oL.+
hU`wVy
*)ardZV${
//count++; 1crnmJ!C
//if(count>4) 3nT^?;-
// siteStop(); 87<-kV
} $@^pAP
K`iv c N"
i]Fp..`v~
System.err.println("文件下载结束！"); *BR~}1 i
} ;> _$`
catch(Exception e){e.printStackTrace ();} OMWbZ>jB
} F~%]6^$w
[Sr,h0h6
8YZbP5'
//获得文件长度 T]t+E'sQ
public long getFileSize() A )^`?m3
{ GN ]cDik
int nFileLength = -1; T&%ux=Jt
try{ Kqp(%8mf
URL url = new URL(siteInfoBean.getSSiteURL()); G;v8$)Zj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #33fGmd[
httpConnection.setRequestProperty("User-Agent","NetFox"); r"``QmM
%X4xv_o`f
tk!t Y8j
int responseCode=httpConnection.getResponseCode(); TD'L'm|2
if(responseCode>=400) aGJC1x
{ As3.Q(#Z
processErrorCode(responseCode); LQ(yScA@
return -2; //-2 represent access is error [s"O mAy4
} 4{hps.$?~
QW$G
jGXO\:sO
String sHeader; ofPHmh`
UUzYbuS>&l
=NnNN'}
for(int i=1;;i++) i=i(%yQ%
{ v@Gl|29_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "}q@Y=
//Utility.log(in.readLine()); OK{quM5
sHeader=httpConnection.getHeaderFieldKey(i); tSVc|j
if(sHeader!=null) qQA}Z*(m
{ k5D%y3|9
if(sHeader.equals("Content-Length")) (@%gS[]
{ V.O(S\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xl6,s>ob
break; giZP.C"0
} +Vm}E0Ov
} o*DN4oa)
else rG4';V^q
break; MS\>DW
} !G SV6
} v%"|WV[N
catch(IOException e){e.printStackTrace ();} 85n1eE
catch(Exception e){e.printStackTrace ();} D}dn.$
iVB86XZ`
wF|fK4F
Utility.log(nFileLength); NWM8[dI
V n*
3pv4B:0
return nFileLength; O-LO/*5MI
} `D=S{
S/D^
R]OpQ[k
//保存下载信息（文件指针位置） )z&/_E=
private void write_nPos() 'NX```U0
{ #9X70|f
try{ /LO-HnJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); f!s=(H;
output.writeInt(nStartPos.length); Zb1<:[
for(int i=0;i<nStartPos.length;i++) q:dHC,fO
{ t.laO. 3
// output.writeLong(nPos); /9HVY %n
output.writeLong(fileSplitterFetch.nStartPos); k Mu8"Az
output.writeLong(fileSplitterFetch.nEndPos); *^f<W6xc
} lTd #bN
output.close(); x7~r,x(xM
} rW+ =,L
catch(IOException e){e.printStackTrace ();} H-~6Z",1
catch(Exception e){e.printStackTrace ();} QA<Jr5Ys
} XmEq2v
GM3f-\/
qOSM}ei>s
//读取保存的下载信息（文件指针位置） w*oeK
private void read_nPos() 4<%*E{`
{ nq6@6GRG
try{ :/Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \~fONBY
int nCount = input.readInt(); {5F-5YL+>
nStartPos = new long[nCount]; +n#V[~~8AI
nEndPos = new long[nCount]; $e*ce94
for(int i=0;i<nStartPos.length;i++) m|{3),#V
{ }HY-uQ%@g
nStartPos = input.readLong(); w+yC)Rmz
nEndPos = input.readLong(); F)W:
} _>| =L W@7
input.close(); R~)\3] "2m
} @7?#Y|`
catch(IOException e){e.printStackTrace ();} kg'o&^/=
catch(Exception e){e.printStackTrace ();} {vuZ{IJa
} KU8Jbl*
E=>FjCsu<-
.ox8*OO<
private void processErrorCode(int nErrorCode) &Rvm>TC=
{ 1XD,uoxB
System.err.println("Error Code : " + nErrorCode); @>p<3_Y1
} j!]YNH@
fZ*+2T>
hRs&t,{&
//停止文件下载 CCL
public void siteStop() QKr,g
{ ^R# E:3e
bStop = true; ptU\[Tq
for(int i=0;i<nStartPos.length;i++) *T5!{
fileSplitterFetch.splitterStop(); w]]8dz
]=>F.GE
. koYHq
} =~=*&I4Dp
} C!fMW+C@
//负责部分文件的抓取 BFo5\l:q8
**FileSplitterFetch.java LUqB&,a}
*/ [[;e)SoA
package NetFox; 6f\Lf?vF
}Q=!Y>Tc
dvt9u9Vg=
import java.io.*; T3k#VNH
import java.net.*; vvKEv/pN7
A1.7O
zmSUw}-4N
public class FileSplitterFetch extends Thread { _Em.
><gG8MH0'
pKit~A,Q
String sURL; //File URL bT^I"
long nStartPos; //File Snippet Start Position 5u*-L_
long nEndPos; //File Snippet End Position 'H \9:7
int nThreadID; //Thread's ID no< ^f]33
boolean bDownOver = false; //Downing is over @>W(1mRi
boolean bStop = false; //Stop identical Z@]e{zO
FileAccessI fileAccessI = null; //File Access interface . r[Hu40p
DV<` K$ET
cd$m25CxC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a{ ?`t|
{ PfC!lI BU
this.sURL = sURL; I?ae\X@M
this.nStartPos = nStart; %Ti}CwI`
this.nEndPos = nEnd; m^GJuPLW
nThreadID = id; Si6al78
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2vAQ
} =o&>fw
a2 Y;xe
o]; [R
public void run() L$IQuy
{ G0^2Wk[
while(nStartPos < nEndPos && !bStop) 6~1|qEe6I
{ ~TSy<t~%-
gx\&_)w N
>hk=VyU;
try{ )u/yF*:n
URL url = new URL(sURL); QA5QweL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HN&Z2v
httpConnection.setRequestProperty("User-Agent","NetFox"); FRg^c kb"
String sProperty = "bytes="+nStartPos+"-"; Aq0S-HKF
httpConnection.setRequestProperty("RANGE",sProperty); >rJnayLF
Utility.log(sProperty); S$Q8>u6Wk
]>~)<
M;p em<
InputStream input = httpConnection.getInputStream(); IHJ=i-
//logResponseHead(httpConnection); /J:bWr
BV>\ McI+
2@%$;.
byte[] b = new byte[1024]; <iH`rP#
int nRead; ^OstR`U3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h $L/<3oP6
{ (UU(:/
nStartPos += fileAccessI.write(b,0,nRead); ]cGA~d
//if(nThreadID == 1) A7%:05
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UG'9*(*
} XVvK2(
5ZMR,SZhC
G|( ]bvJ?
Utility.log("Thread " + nThreadID + " is over!"); j}~86JO+Cw
bDownOver = true; 2Fq<*pxAY
//nPos = fileAccessI.write (b,0,nRead); BPdfYu,il
} o[cV1G
catch(Exception e){e.printStackTrace ();} l,,>& F
} pBETA'fY
} }RwSp!}C
S%yd5<%_
a^=-Mp
//打印回应的头信息 3WUTI(
public void logResponseHead(HttpURLConnection con) ($}`R xj1@
{ :&:JTa1cv
for(int i=1;;i++) TW[_Ko86
{ ?)`L$Vr=
String header=con.getHeaderFieldKey(i); 5lm<%
if(header!=null) d"6&AJ5a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c2e tc8
Utility.log(header+" : "+con.getHeaderField(header)); ?zQA
else K9OYri^TQ
break; xv&Q+HD
} qeL5D*
} JvT"bZk(o
}(1JaG
~fT_8z
public void splitterStop() pb$~b\s]=
{ WV#%PJ
bStop = true; v7DE
} _ B5gR
zJ)*Z,7
'rr^2d]`ST
} il \$@Bn
p~9vP)74u
OnK~3j
/* D;_ MPN[
**FileAccess.java G=A,9@+c
*//文件访问(定位，写) T`Mf]s)*
package NetFox; JXu$ew>q
import java.io.*; w\DVzeW(
pGK;1gVj
l"2OP6d
public class FileAccessI implements Serializable{ w*|7!iM
{WPobP"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qbyv{/
RandomAccessFile oSavedFile; R8T]2?Q1
long nPos; '*k'i;2/1
tWoh''@#
GF5^\Rf
public FileAccessI() throws IOException E5N{j4\F
{ hYM@?/(q
this("",0); Xa[?^P
} ;\\@q"n%<
Vgyew9>E
6p?JAT5
public FileAccessI(String sName,long nPos) throws IOException \@1=stK:F
{ &bp=`=*
oSavedFile = new RandomAccessFile(sName,"rw"); e`v`XSA[p
this.nPos = nPos; @$2))g`
oSavedFile.seek(nPos); %o:2^5\W
} I<8sI%,s
|7}CQU
a'jR#MQl?
public synchronized int write(byte[] b,int nStart,int nLen) ?zsB6B?;
{ 9`w)
int n = -1; HH@qz2w
try{ ^>N]H>0'S
oSavedFile.write(b,nStart,nLen); 'qF#<1&
n = nLen; `A,g] 1C:
} A%{W{UP8N
catch(IOException e) LJ(1RK GCz
{ A^2Uzmzl?
e.printStackTrace (); &g~ wS@
} KhW;RD
}GZ}Q5
`p7&> BOA
return n; K%Rj8J7|u?
} {nvLPUL
GKFq+]W
3RR_fmMT)
} 1[t=XDz/e
U=o"32n+
't9hXzAfW
/* _+^ 2^TW
**SiteInfoBean.java =l0Jb#d
*/ }QsZ:J.
package NetFox; 2d {y M(=(
{|yob4N
fz3lV
public class SiteInfoBean { ~35U]s@v
/2HN>{F^Y
Cc, `}SP
private String sSiteURL; //Site's URL 7zv1wb
private String sFilePath; //Saved File's Path ]+m/;&0
private String sFileName; //Saved File's Name m/@<c'i
private int nSplitter; //Count of Splited Downloading File 9Y<#=C
C>[fB|^
A,)VM9M_l
public SiteInfoBean() ,E$@=1)
{//nSplitter的缺省值为5 _C+b]r/E
//default value of nSplitter is 5 XbZ*&
this("","","",5); 60)iw4<wf
} hAjM1UQ,Y
d)"?mD:m/M
bC3 F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4ON_$FUe
{ I6s3+x;O
sSiteURL= sURL; |/|
sFilePath = sPath; `WOYoec
sFileName = sName; yj$TPe_BW
this.nSplitter = nSpiltter; ,.o<no
U7DCx=B
>R2SQA o
} d|*"IFe
wV)}a5+
\xUe/=
public String getSSiteURL() !!:LJ
{ wHem5E
return sSiteURL; ;kJu$U
} 2Gs$?}"a
.?>5-od2
snt(IJQ
public void setSSiteURL(String value) 7 uarh!
{ n 8pt\i0
sSiteURL = value; _6Eu2|vM&
} D>!6,m2
eJo3 MK
/LM4-S
public String getSFilePath() rO:u6."_
{ cf7v[ZZ}
return sFilePath; w?,M}=vg
} KnNh9^4"\2
}rdIUlVO\
c0Dmq)HK?
public void setSFilePath(String value) kpI{KISQu
{ \M"UmSB o
sFilePath = value; olW|$?
} 6ITLGA
*E~VKx1
5eA8niq#
public String getSFileName() jkF8\dR
{ :EtMH(
return sFileName; '>v^6iS
} =U. b% uC
D5an\gE
X{g%kf,D=
public void setSFileName(String value) gLSA!#[h
{ $y?k[Y-~
sFileName = value; G3G6IP
} =9LC<2
f):~8_0b
R4<lln:[
public int getNSplitter() z1!6%W_.
{ oy<J6
return nSplitter; 2 /y}a#s
} oR*=|B
M- 0i7%
do-c1;M
public void setNSplitter(int nCount) CWO=0_>2
{ mga6[E<
nSplitter = nCount; Se!)n;?7Sw
} Fn^C{p^
} GyC/_ntn
- /c7nF
%k0EpJE%
/* R1-k3;v^
**Utility.java J@9}`y=K
*/ ~^vC,]hU
package NetFox; -K[782Q
T#O??3/%$1
jvVi%k
public class Utility { b8f+,2Tk
"*7C`y5&P
*g;-H&`
public Utility() <TNk?df7
{ ^\:2}4Uj_
(H?ZSeWx
Z7jX9e"L
} o;[bJ Z\^x
[k]|Qink
//线程睡眠 nVD Xj
public static void sleep(int nSecond) Yn9j-`
{ vRPS4@9'
try{ }xFi& <
Thread.sleep(nSecond); -iCcoA
} &D#+6M&LK{
catch(Exception e) +[m8c){
{ <1&Ke
e.printStackTrace (); <3hA!$o~
} K<v:-TjQZ:
} ,PWj_}|L[
9YF$CXonE=
//日志 s T3p>8n
public static void log(String sMsg) :Y)to/h
{ (RXS~8
System.err.println(sMsg); D*vm cSf
} Pj7gGf6v
Ak~4|w-
cbKL$|
public static void log(int sMsg) 6(sIYZ2yq
{ S2~@nhO`U(
System.err.println(sMsg); }iIbcA
} `eRLc}aP2
} J<JBdk
)'q%2%Ak
A2x;fgi
/* |)@N-f:E
**TestMethod.java -cNx1et
*/ gY`Nr!O
package NetFox; | W#~F&{]
OYf{?-QD
~_!ts{[E
public class TestMethod { Xz;b,C&*t
MY-.t-3
a%hGZCI
public TestMethod() @XOi62(
{ ///xx/weblogic60b2_win.exe G+)?^QTn
try{ |Vx~fKS\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -O&"|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z^sST
SiteFileFetch fileFetch = new SiteFileFetch(bean); GH'O!}
fileFetch.start(); {TZE/A3D,
} u9![6$R
catch(Exception e){e.printStackTrace ();} |0{ i9.=
Kla:e[{
um8AdiK
} R9.HD?H@
FsCwF&/q
'o\;x"YJ
public static void main(String[] args) QJ];L7Hbo
{ L(WOet('
new TestMethod(); _g6m=N4
} Sb^ b)q"
} gJ\%>r7h
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