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)); ufo?ZFq@$L
} LgaJp_d>9*
for(int i=0;i<nEndPos.length-1;i++) N>z8\y
{ @s/ qOq?
nEndPos = nStartPos[i+1]; +VeLd+Q}
} *dTw$T#
nEndPos[nEndPos.length-1] = nFileLength; {tMD*?C[6
} ~\^8 ^
} 2O
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?=vwr,ir
//启动子线程 -(2-zznZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ANNL7Z3C
for(int i=0;i<nStartPos.length;i++) "6}+|!"$
{ {kzM*!g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), spI{d!c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /t/q$X
nStartPos,nEndPos,i); T;%SB&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Du*Re6g
fileSplitterFetch.start(); Gnw>%f1@u
} ;~K($_#H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [brrziZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J0oR]eT}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5|b/G
nEndPos = " + nFileLength); 1@ina`!1O
// fileSplitterFetch[nPos.length-1].start(); wVvU]UT
cnsGP*w
w"e2}iE7
//等待子线程结束 ?R+$4;iy
//int count = 0; pr?/rXw
//是否结束while循环 Ju\"l8[f
boolean breakWhile = false; -7`J(f.rYC
Mc8^{br61
k (R4-"@
while(!bStop) C+k>Ajr
{ v!uLd.(
write_nPos(); <(^pHv7Q
Utility.sleep(500); vuAjAeKm
breakWhile = true; ]]7T5'.
B8&@Qc@~
ovohl<o\
for(int i=0;i<nStartPos.length;i++) PTP2QAt
{ I,[EL{fz
if(!fileSplitterFetch.bDownOver) YU`{
{ WIghP5%W
breakWhile = false; usA!MMH4
break; U}7[8&k1
} u|ZO"t
} 3:gk:j#
if(breakWhile) lDpi1]2
break; kel {9b=i
H1]\B:
`zL9dlZ
//count++; $CmTsnR1#y
//if(count>4) ?,NAihN]
// siteStop(); kr?|>6?
} *+AP}\p0F
*}J_STM
?Y9?x,x
System.err.println("文件下载结束！"); D8ly8]H
} #59zv=
catch(Exception e){e.printStackTrace ();} )N/KQ[W
} YV msWuF
X]!@xlwF\
[=Z{y8#:J
//获得文件长度 8n)Q^z+ K
public long getFileSize() [h1{{Nb#ez
{ *.RVH<W=8
int nFileLength = -1; 0#JBz\
try{ lySaJd
URL url = new URL(siteInfoBean.getSSiteURL()); UQFuEI<1-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^wlep1D
httpConnection.setRequestProperty("User-Agent","NetFox"); Ir'f((8:
{ SfU!
F\I^d]#,[
int responseCode=httpConnection.getResponseCode(); k-U/x"Pl
if(responseCode>=400) &u8c!;y$b
{ 55,-1tWs
processErrorCode(responseCode); [xPE?OD
return -2; //-2 represent access is error {>Px.%[<
} 2?j1~]DvZ
AMdS+(J
K="+2]{I
String sHeader; UwU]l17~
@jHio\/_
6,PLzZ5
for(int i=1;;i++) i`qh|w/b_
{ .p`'^$X^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U4gwxK
//Utility.log(in.readLine()); H<;j&\$q
sHeader=httpConnection.getHeaderFieldKey(i); MeX1y]<It
if(sHeader!=null) WQx;tX
{ 9x!y.gx
if(sHeader.equals("Content-Length")) sYpogFfV
{ ;Y\,2b, xh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \4k*Zk
break; #pfosC[
} LnGSYrx1
} OT i3T1&
else }b`*%141
break; AHGcWS\,X
} ;^]A@WN6_
} j`B{w
catch(IOException e){e.printStackTrace ();} S41>VbtEp
catch(Exception e){e.printStackTrace ();} 1tdCzbEn+
/5Loj&!=
R`q!~8u
Utility.log(nFileLength); 1tW:(~=a;
G.8b\E~
@_3$(*n$~
return nFileLength; [3Rj?z"S
} L:-lqag!
V-jL`(JF%
}c%y0)fL
//保存下载信息（文件指针位置） !`lqWO_/ :
private void write_nPos() `'WLGQG
{ [<QWTMjR
try{ Umg81!
output = new DataOutputStream(new FileOutputStream(tmpFile)); |T*qAJ8c
output.writeInt(nStartPos.length); m{c#cR
for(int i=0;i<nStartPos.length;i++) QEa=!O
{ K8Zk{on
// output.writeLong(nPos); /&7Yi_]r
output.writeLong(fileSplitterFetch.nStartPos); (_ah~VnO
output.writeLong(fileSplitterFetch.nEndPos); avu,o
} %<yM=1~>
output.close(); J-F_XKqH
} uszSFe]E
catch(IOException e){e.printStackTrace ();} mC92J@m/L!
catch(Exception e){e.printStackTrace ();} :g#it@
} NCt sx /C
6a?p?I K^
KTt$Pt/.
//读取保存的下载信息（文件指针位置） R"`{E,yj
private void read_nPos() `gN68:B
{ ^~ $&
try{ nX%'o`f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g/p9"eBpq
int nCount = input.readInt(); .N&}<T[
nStartPos = new long[nCount]; 7"ps#)O
nEndPos = new long[nCount]; bK9~C" k
for(int i=0;i<nStartPos.length;i++) ^1=|(Z/
{ vp-7>Wj
nStartPos = input.readLong(); J5_Y\@
nEndPos = input.readLong(); mX@*2I
} s$x] fO
input.close(); yMl'1W
} Ba|}C(Ws?
catch(IOException e){e.printStackTrace ();} K"j=_%{
catch(Exception e){e.printStackTrace ();} 5KE%@,k k
} +|)1_NK
2EwWV0BS
NqE7[wH
private void processErrorCode(int nErrorCode) LoE(W|nj
{ &xroms"S=
System.err.println("Error Code : " + nErrorCode); k<zGrq=8J
} i03}f%JnuO
)=nPM`Jn.
UQ])QTrZFi
//停止文件下载 N('DIi*or
public void siteStop() O>M*mTM
{ Pl&`&N;
bStop = true; l~TIFmHkh%
for(int i=0;i<nStartPos.length;i++) &iy(oM
fileSplitterFetch.splitterStop(); N3p 7 0
3H#/u! W
p6*a1^lU6
} cN}A rv
} I S8nvx\
//负责部分文件的抓取 p[F=LP
**FileSplitterFetch.java -u9yR"n\}
*/ \}QuNwc
package NetFox; H9Q7({v
}9udo,RWu
w<>6>w@GZ
import java.io.*; ivz9R'
import java.net.*; &9w%n
G4%M$LJh
1 lCikS^c
public class FileSplitterFetch extends Thread { bL],KW;Q
WfT)CIKs
R|J>8AL}BY
String sURL; //File URL 3r:)\E+Q_
long nStartPos; //File Snippet Start Position NwlRPyt
long nEndPos; //File Snippet End Position *R\/#Y|
int nThreadID; //Thread's ID dN\P&"`
boolean bDownOver = false; //Downing is over qvU$9cTY
boolean bStop = false; //Stop identical =>}.W:=
FileAccessI fileAccessI = null; //File Access interface Z F yX@#B9
}42qMOi#w1
uj9tr`Zh
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p/WH#4Xdr
{ 4:eq{n
this.sURL = sURL; Y:!/4GF
this.nStartPos = nStart; hf+/kc!>i
this.nEndPos = nEnd; ]RXtC*
nThreadID = id; K*U=;*p)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gLSG:7m@
} Z++Z@J"
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public void run() -8Jl4F ,
{ *- IlF]
while(nStartPos < nEndPos && !bStop) R-A'v&=
{ ?+,*YVT
PMN2VzE4{
7hF,gl5
try{ ~r>EF!U`h
URL url = new URL(sURL); s 9|a2/{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xngeV_xc2
httpConnection.setRequestProperty("User-Agent","NetFox"); ELrZ8&5G
String sProperty = "bytes="+nStartPos+"-"; jQxPOl$-
httpConnection.setRequestProperty("RANGE",sProperty); (O_t5<A*X
Utility.log(sProperty); o(d_uJOB
*0&4mi8
2 ]DCF
InputStream input = httpConnection.getInputStream(); FJd8s*
//logResponseHead(httpConnection); k99gjL`
Q3Z%a|3W
3$$5Mk(&
byte[] b = new byte[1024]; tFvgvx\:
int nRead; [}p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TvWU[=4Yk
{ =|gJb|?w
nStartPos += fileAccessI.write(b,0,nRead); 3Zaq#uA
//if(nThreadID == 1) vTMP&a'5L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i{|lsd(+
} YHO;IQ5
o%Uu.P
9QC"Od9H
Utility.log("Thread " + nThreadID + " is over!"); |6sT,/6
bDownOver = true; Z{a{HX[Jx
//nPos = fileAccessI.write (b,0,nRead); tKG;k"wk
} 5?3Isw`v2
catch(Exception e){e.printStackTrace ();} ^sT+5M^
} u>,lf\Fgz
} P1 7>6)a
` $.X[\*U
a9D gy_!Y
//打印回应的头信息 /FP~jV!z
public void logResponseHead(HttpURLConnection con) (XbMrPKG
{ aQ!9#d_D
for(int i=1;;i++) X"hOHx5P
{ `d}W;&c
String header=con.getHeaderFieldKey(i); C 'B4 mmC
if(header!=null) 1-6gB@cvQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hi;WFyJTu
Utility.log(header+" : "+con.getHeaderField(header)); 4NpHX+=P
else i(M(OR/4
break; [<D+pqh
} tk`: CT *
} }iPo8Ra
2j8Cv:{Nn%
S}zC3
public void splitterStop() f![xn2T
{ ZhGh{D[,
bStop = true; 9"WRIHt'c
} *oEv,I_
/J1S@-
s~'9Hv9
} f*{M3"$E
<)_:NRjBF&
{[Uti^)m%
/* %:" RzHN
**FileAccess.java CCuxC9i7
*//文件访问(定位，写) Rz`@N`U
package NetFox; v\fzO#vj
import java.io.*; vx04h~
q$MHCq;
>lA7*nn
public class FileAccessI implements Serializable{ l*QIoRYFW
>:.w7LQy/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rU; g0'4e
RandomAccessFile oSavedFile; P7}t lHX
long nPos; 5+y@ ]5&g
*w=z~Jq^R"
nURvy}<r
public FileAccessI() throws IOException 2#'rk'X,K
{ |d~B]65t
this("",0); jZa25Z00
} OF-E6bc
B1y<.1k
&@=u+)^-{
public FileAccessI(String sName,long nPos) throws IOException `ajx hp
{ btUq
oSavedFile = new RandomAccessFile(sName,"rw"); jVX._bEGX
this.nPos = nPos; j'k8^*M6
oSavedFile.seek(nPos); /pO{2[
} _mw13jcN]
53bM+
CIIY|DI`l
public synchronized int write(byte[] b,int nStart,int nLen) UV?[d:\>'
{ =ZG<BG_
int n = -1; "=9-i-K9B
try{ d0'7efC+
oSavedFile.write(b,nStart,nLen); zs4>/9O
n = nLen; P`}$-#DF
} Mg#`t$u
catch(IOException e) U%Dit
{ j -#E?&2
e.printStackTrace (); \^yXc*C
} =nLO?qoe
'^hsH1
sjSi;S4
return n; "PMO
} T&]Na
vxb@9eb!H
bk.*k~_
} %WZ$]M?q
iA]DE`S
:*=Ns[Y
/* (m6EQoW^s+
**SiteInfoBean.java Ys-^7 y_
*/ '[%jjUU
package NetFox; B<Ol+)@,}
kPWBDpzN
V)=Z6ti
public class SiteInfoBean { >Dxe>Q'df
*E.LP1xP
)5U!>,fT
private String sSiteURL; //Site's URL XWJ SLN(O
private String sFilePath; //Saved File's Path 5~QhX22
private String sFileName; //Saved File's Name k<!<<,Z
private int nSplitter; //Count of Splited Downloading File Ha?G=X
KVg[#~3
JT}.F!q6E
public SiteInfoBean() uN8/Q2
{//nSplitter的缺省值为5 ti}f&w ICJ
//default value of nSplitter is 5 3+e4e
this("","","",5); aFyh,
} 7q!?1 -?8R
pKq]X}[^c
7"#f!.E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ><cU7 ja[^
{ eap8*ONl
sSiteURL= sURL; .wP/ai>}
sFilePath = sPath; Vn^)
sFileName = sName; w;~>k%}j
this.nSplitter = nSpiltter; z4bN)W )p
\Y+")
)Z("O[
} nX)f'[ 7
~JLYhA^'+<
-A}zJBcR
public String getSSiteURL() a#$N%=j
{ G?R_aPP
return sSiteURL; X{`1:c'x
} zz&vfO31J
L1:nfH&:'
MF^_Z3GS'
public void setSSiteURL(String value) ##v`(#fu
{ |U EC
sSiteURL = value; !3@{U@*Z]
} Ia#"/`||
h D.)M
^zgacn
public String getSFilePath() ?,>5[Ha^?
{ Ch t%uzb,
return sFilePath; #~S>K3(
} 6Kp}_^|z
"b`7[;a
hXc}r6<B
public void setSFilePath(String value) O>%$q8x@i
{ 0yaMe@&,
sFilePath = value; Kr]z]4.d@
} J0sGvj{
-x{&an=
JCD?qeTg
public String getSFileName() Z%OW5]q
{ rI>LjHP
return sFileName; *7Xzht&f
} _4v"")Xe
I|T7+{5z
uFo/s&6K
public void setSFileName(String value) \E77SO,$
{ Mb.4J2F?
sFileName = value; ?!y"OrHg
} Zw#<E =\
7h`^N5H.q
^KbL ,T
public int getNSplitter() xCq'[9oU
{ 'g hys1H
return nSplitter; b]i>Bv
} 7]Rk+q2:
3ev-Iqz
Kp&3=e;vn{
public void setNSplitter(int nCount) )NIv "Q
{ 5gshKmt_
nSplitter = nCount; qnXTNs ?b
} |IN[uQ
} kC`Rd:5
3+V#[JBJv
>pdnCv_c
/* RX>2~^
**Utility.java 9`Vc
*/ vBoO'l9'M
package NetFox; y\,f6=%k
q:]Q% IC^
;7j,MbU
public class Utility { `tVy_/3(9
Z0\Iyc G
J@Yj\9U
public Utility() n[CoS
{ EEwWucQ
CA*~2|
328L)BmW
} (w$'o*z;(
U\bC0q
//线程睡眠 vQHpf>o
public static void sleep(int nSecond) ="(>>C1-
{ _ZyT3P&
try{ K*+6`z#fMF
Thread.sleep(nSecond); [.&[<!,.
} GTAf
catch(Exception e) %/pc=i|+
{ NwpS)6<-
e.printStackTrace (); &,MFB
} V.VJcx
} >lLo4M 3
&<0ZUI |S3
//日志 ?cK]C2Ak
public static void log(String sMsg) B9#;-QO
{ P }Te"Y
System.err.println(sMsg); JA6";fl;
} ri=+(NKo-
iLtc HpN
(p,}'I#i*
public static void log(int sMsg) Pm?B 9S
{ e=>%^F
System.err.println(sMsg); D^?_"wjW
} l$M +.GB<
} 8xTix1u0
28UVDG1?
A*i_|]Q
/* mH\@QdF
**TestMethod.java 1;&T^Gdj
*/ nk/vGa4
package NetFox; 0>@[o8
M-Sv1ZLh
RxG^
public class TestMethod { P {H{UKs#
38Efp$)
Ue7 6py9
public TestMethod() ;k}H(QI
{ ///xx/weblogic60b2_win.exe hQ';{5IKvC
try{ Zi{0-m6+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +)gB9DoK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F1c&0*_A
SiteFileFetch fileFetch = new SiteFileFetch(bean); !G+u j(
fileFetch.start(); 28oJFi]
} MZ~.(&
catch(Exception e){e.printStackTrace ();} o^GC=Aca`
o;QZe&
&HL{LnLP@/
} w~N-W8xNR
K\^&+7&zVg
rBfg*r`)
public static void main(String[] args) w+_Wc~f
{ TSQhX~RN
new TestMethod(); *h:kmT
} VGZ6
} 2 ~-( A
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