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)); ]@z!r2[
} &77J,\C$:
for(int i=0;i<nEndPos.length-1;i++) &2 Yo
{ n^;-&
nEndPos = nStartPos[i+1]; {ObY1Y`ea
} h/\Zq
nEndPos[nEndPos.length-1] = nFileLength; t=Rl`1=(K
} 3Y)z{o>P
} hk5!$#^
>ph=?MKD
%1k"K~eu
//启动子线程 |;a$ l(~<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t'$_3ml
for(int i=0;i<nStartPos.length;i++) n-M6~
{ F-:AT$Ok
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `$1A;wg<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TxQsi"0c
nStartPos,nEndPos,i); SHPDbBS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d1g7:s9$0
fileSplitterFetch.start(); (G+)v[f
} :^?-bppYW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,/p+#|>C=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ou4hAm91s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,ov$`v
nEndPos = " + nFileLength); {wSz >,
// fileSplitterFetch[nPos.length-1].start(); .R`_"7
/PaS<"<P@
P|ibUxSA~,
//等待子线程结束 J3aom,$o
//int count = 0; }KUK|p5
//是否结束while循环 !U4YA1>>
boolean breakWhile = false; g/$RuT2U
GL0P&$h
\bF<f02P
while(!bStop) R$u1\r1I
{ F7C+uGTs
write_nPos(); ? }ff O
Utility.sleep(500); XLiwE$:t%
breakWhile = true; ~u0<c:C^
/<T{g0s
w]xr ~D+
for(int i=0;i<nStartPos.length;i++) gAEB
{ w$&;s<0
if(!fileSplitterFetch.bDownOver) .u&X:jOE
{ H'$H@Kn]-
breakWhile = false; :##$-K*W"
break; y]R+/
} vD#kH1
} voRb>xF
if(breakWhile) =YO<.(Lu
break; NoF|j57?u'
B)DuikV.D
nvQX)Xf
//count++; jpYZ) So-
//if(count>4) KIY`3Fl09
// siteStop(); u"7!EhX&
} L^CB#5uG
5>S1lyam
mmjWLrhlu
System.err.println("文件下载结束！"); ?vWF[ DRd'
} _ j'm2BAO
catch(Exception e){e.printStackTrace ();} "usPzp5
} G 9 &,`
7ieAd/:_
w?"M
//获得文件长度 Zr6.Nw
public long getFileSize() g*_n|7pB
{ 4!ZT_q
int nFileLength = -1; >@G"*le*)
try{ y~OP9Tg
URL url = new URL(siteInfoBean.getSSiteURL()); t}}Ti$$>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \O~/^ Y3U!
httpConnection.setRequestProperty("User-Agent","NetFox"); 3e-E/6zH6
ep5`&g]3
:>ca).cjac
int responseCode=httpConnection.getResponseCode(); b O}&i3.L;
if(responseCode>=400) +,7vbs3
{ _I,GH{lhI
processErrorCode(responseCode); 4;32f`
return -2; //-2 represent access is error Y0Tw:1a
} fY=:geB
hc]p^/H
:!$+dr(d
String sHeader; #Ddo` >`&
OqH3.@eK
58mpW`Q
for(int i=1;;i++) <f)T*E^5%
{ 'Zex/:QS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sc-hO9~k
//Utility.log(in.readLine()); M.qv'zV`xG
sHeader=httpConnection.getHeaderFieldKey(i); 1n6%EC|X
if(sHeader!=null) H;AMRL o4z
{ ]d{lS&PRlg
if(sHeader.equals("Content-Length")) `25<;@
{ )3|a_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p74Nd4U$s
break; |#xBC+
} 3H>\hZ
} P%R9\iajH
else ;ioF'ov
break; N?,
} BVus3Y5IJQ
} [ gR,nJH.
catch(IOException e){e.printStackTrace ();} eMn'z]M&]
catch(Exception e){e.printStackTrace ();} PN J&{4wY
64"DT3:
}=gD,]2x8
Utility.log(nFileLength); C(>g4.-p8
h'vBWtMa
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return nFileLength; NTCFmdbs 6
} TZg1,Z
t1yfSStp
&oZU=CN
//保存下载信息（文件指针位置） 77+3CME{'
private void write_nPos() ZifDU@J$t
{ z.h;}QRJ,@
try{ ?djH!
output = new DataOutputStream(new FileOutputStream(tmpFile)); I^n,v) 8
output.writeInt(nStartPos.length); tblduiN
for(int i=0;i<nStartPos.length;i++) # eFdu
{ &VCg`r-{~
// output.writeLong(nPos); EKQ>hww8
output.writeLong(fileSplitterFetch.nStartPos); )@tHS-Jf
output.writeLong(fileSplitterFetch.nEndPos); F]<2nb7
} 96; gzG@1!
output.close(); Ut/%+r"s
} r1=j$G
catch(IOException e){e.printStackTrace ();} 8y[Rwa
catch(Exception e){e.printStackTrace ();} #l9sQ-1Q
} ?y"M>#
`q | )_
R S>qP;V*-
//读取保存的下载信息（文件指针位置） 4OAR["f
private void read_nPos() Pv)^L
{ 3-Xd9ou
try{ =jxy4`oF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "|,KXv')
int nCount = input.readInt(); R7h3O0@!
nStartPos = new long[nCount]; /74h+.amg
nEndPos = new long[nCount]; ru1^.(W2
for(int i=0;i<nStartPos.length;i++) f1U8 b*F<
{ v7hw%9(=
nStartPos = input.readLong(); nC?Lz1re
nEndPos = input.readLong(); VT~%);.#
} `]l|YQz\
input.close(); a>d`g
} +`$$^x
catch(IOException e){e.printStackTrace ();} X(#8EY}X
catch(Exception e){e.printStackTrace ();} yVKl%GO
} |-cXb.M[
Z@*!0~NH=4
*<"{(sAvk
private void processErrorCode(int nErrorCode) *p\fb7Pu_3
{ D=.Ob<m`Z
System.err.println("Error Code : " + nErrorCode); kf|J
} ;v.J D7
r%$\Na''
{(tR<z)
//停止文件下载 /9Qr1@&v
public void siteStop() ]HXHz(?;F
{ Oc.8d<
bStop = true; \;Q!}_ K
for(int i=0;i<nStartPos.length;i++) hOFvM&$
fileSplitterFetch.splitterStop(); >r}?v3QW
~Dw% d;
n\BV*AH
} utn,`v
} 3rJ LLYR
//负责部分文件的抓取 ,I]]52+?4
**FileSplitterFetch.java tqpi{e
*/ S<i.O
package NetFox; 2#/sIu-L
Yn?Xo_Y
U.I7p
import java.io.*; 4v{Ye,2
import java.net.*; qwn EVjf
pu?COA
[T/S/@IT
public class FileSplitterFetch extends Thread { 0=40}n&`
m*i,|{UZ
Imclz4'8
String sURL; //File URL +br' 2Pn
long nStartPos; //File Snippet Start Position JP^x]t:
long nEndPos; //File Snippet End Position $GhL-sqm
int nThreadID; //Thread's ID 5'w&M{{9
boolean bDownOver = false; //Downing is over OCCC' k
boolean bStop = false; //Stop identical +t Prqv"(
FileAccessI fileAccessI = null; //File Access interface vD/l`Ib:
1g$xKe~]4
J{XRltI+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I1K%n'D
{ ^R(=4%8%"
this.sURL = sURL; wM-H5\9n
this.nStartPos = nStart; ?zVE7;r4U
this.nEndPos = nEnd; D)S_ p&
nThreadID = id; 1r*@1y<0"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VuK>lY&
} 0r!F]Rm-^
pQ4HX)<P
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public void run() PB BJ.!Pb
{ '[_.mx|cd`
while(nStartPos < nEndPos && !bStop) FBzsM7]j
{ a6It1%a+
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k!WeE#"(
try{ 2$o\`^dy
URL url = new URL(sURL); x>A[~s"|N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m<*+^JN
httpConnection.setRequestProperty("User-Agent","NetFox"); !#e+!h@
String sProperty = "bytes="+nStartPos+"-"; WVp6/HS
httpConnection.setRequestProperty("RANGE",sProperty); ]zIIi%
Utility.log(sProperty); NMrf I0tbG
"st+2#{
OKu~Nb*
InputStream input = httpConnection.getInputStream(); Z\n^m^Z =
//logResponseHead(httpConnection); EF9Y=(0|
qn}VW0!
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byte[] b = new byte[1024]; wCj)@3F
int nRead; hwi_=-SL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pm[i#V<v
{ Aq>?G+
nStartPos += fileAccessI.write(b,0,nRead); /h]ru SI
//if(nThreadID == 1) C?<-`$0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y T&#k1
} z 61Fq
REsw=P!b
G"6XJYoI
Utility.log("Thread " + nThreadID + " is over!"); Vk[M .=J
bDownOver = true; Y%r>=Jvu6
//nPos = fileAccessI.write (b,0,nRead); #60gjHYaV
} L[`8 :}M
catch(Exception e){e.printStackTrace ();} Q;nC #cg
} 5HY0 *\
} $ma@z0%8}
%):pfM;b
h2?\A%
//打印回应的头信息 3m$Qd#|
public void logResponseHead(HttpURLConnection con) Qz$nWsD
{ |BD2=7,z
for(int i=1;;i++) Y^8'P /A
{ WU,b<PU &
String header=con.getHeaderFieldKey(i); axN\ZXU
if(header!=null) C!6D /S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |=:hUp Jp
Utility.log(header+" : "+con.getHeaderField(header)); r;wm`(e
else Z:2%gU&W
break; )?6%d
} ={o)82LV
} lB#7j
5as5{"l
'cc{sjG
public void splitterStop() <R%TCVwC@
{ {qCFd
bStop = true; i]qxF&1
} E7/i_Xkk
rA8{Q.L
sx'eu;S
} 1/?K/gL
rcH{"\F_/
3`NSSS
/* ?<Mx*l
**FileAccess.java nm%7e!{m
*//文件访问(定位，写) Re*~C:
package NetFox; 4 DV,f2:R4
import java.io.*; K7i@7
;(K"w*
.4<lw
public class FileAccessI implements Serializable{ zp``e;gY
vM:c70=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t=jG$A
RandomAccessFile oSavedFile; # 00?]6`z
long nPos; {V8uk$
u?'J1\z
p$*P@qm
public FileAccessI() throws IOException ~I~lb/
{ F9A5}/\
this("",0); =&DuQvN,
} sJ5#T iX
%D% Ok7s})
+NeoGnj
public FileAccessI(String sName,long nPos) throws IOException $)6M@S
{ ni<\AF]`
oSavedFile = new RandomAccessFile(sName,"rw"); 8u1?\SYnb
this.nPos = nPos; d-8{}Q
oSavedFile.seek(nPos); \+x#aN\
} 6X!jNh$oF
152LdZevF
2|NQ5OA0
public synchronized int write(byte[] b,int nStart,int nLen) Oa M~rze
{ O]61guxro
int n = -1; '#Do( U'
try{ J\J3'u
oSavedFile.write(b,nStart,nLen); P=s3&NDD
n = nLen; 4`Jf_C
} 'rVB2 `z-
catch(IOException e) Id8e%)
{ DwWm(8&6;}
e.printStackTrace (); *V[I&dKq
} z>'vS+axV
=CjWPZShV
b%d,X-3
return n; ^E~1%Md.
} ^)aj,U[
3/]~#y%2
v`p@djM
} b.9[Vf_G
j*d+WZm8-g
2av=W
/* {Eqx'j
**SiteInfoBean.java QC6QqcOX
*/ Tz0XBH_
package NetFox; _3#_6>=M
Fr2F&NN`D
aNwx~t]G
public class SiteInfoBean { lAo4)
abS3hf
*&V"x=ba,
private String sSiteURL; //Site's URL #nmh=G?\Sm
private String sFilePath; //Saved File's Path I$XwM
private String sFileName; //Saved File's Name ?D(aky#cyc
private int nSplitter; //Count of Splited Downloading File ,kl``w|1M
43~v1pf{!
IIF <Zkpb
public SiteInfoBean() ,|j\x
{//nSplitter的缺省值为5 R38 \&F
//default value of nSplitter is 5 %MEWw
this("","","",5); \XfLTv
} 1Ve~P"w
j+>N&.zs
1@F>E;YjL=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z f>(Y7M
{ Q!I><u
sSiteURL= sURL; WmRu3O
sFilePath = sPath; IGlM} ?x
sFileName = sName; }Nma %6PfV
this.nSplitter = nSpiltter; EoS6t
E?VOst&
]O0u.=1k
} PWO5R]
6_:KFqc W
k,ezB+
public String getSSiteURL() Qv)DSl
{ &vfeBth
return sSiteURL; ?=HoU3
} J0o,ZH9
<~u-zaN<W
3{TE6&HIa
public void setSSiteURL(String value) zy|h1.gd
{ Z2-"NB
sSiteURL = value; aY DM)b}
} =4OV }z=I
}C$D-fH8sW
nj-LG!"a
public String getSFilePath() 1KjzKFnb
{ tg9{(_t/W
return sFilePath; Zq:c2/\c}
} lg{M\ +
u)%/df qzZ
R~;8v1>K
public void setSFilePath(String value) 7&(h_}Z
{ tqL2' (=
sFilePath = value; 6H;\Jt
} mApl;D X
+,)Iv_Xl$
JZJb&q){
public String getSFileName() BHU=TK@GR
{ '<O.J(N~4!
return sFileName; Kp!A ay
} UlPGB2B
3PkU>+.6
?.c:k;j
public void setSFileName(String value) 6w_TL<S
{ =%B}8$.|
sFileName = value; *o<|^,R
} O>9-iqP>`d
v9Lf|FXo&
2;w> w#}>
public int getNSplitter() iT+t
{ AdzdYZiM_
return nSplitter; s=Kz9WLy
} &3itBQF
=p dLh
474 oVdGx
public void setNSplitter(int nCount) 1k{H,p7
{ (@bq@0g
nSplitter = nCount; QoMa+QTuc
} 9Fg:
} .Y }k@T40a
+6L.a3&(b
/2 qxJvZ
/* }|j#C[
**Utility.java vorb?iVf>
*/ bzZ7L-yD
package NetFox; y`cL3 xr4R
VmZDU(M
OD?y
public class Utility { ?Iag-g9#=m
j#YVv c%
a;&0u>
public Utility() TeyFq0j@'
{ .g.glQ_~=
*r|13|k
(v$ i
} Qz$Wp*
TZdJq
//线程睡眠 l .m #
public static void sleep(int nSecond) 0;%\L:,O
{ x6vkd%fCj
try{ 4z^~,7J^
Thread.sleep(nSecond); 5H( ]"C
} w*u.z(:a`
catch(Exception e) iL~(BnsF
{ _j~y;R)
e.printStackTrace (); !|cM<}TF,
} :\%hv>}|
} B|=S-5pv*
Qh]k)]+*|
//日志 ]|[mwC4
public static void log(String sMsg) 7(H?3)%0
{ SE$l,Z"[*b
System.err.println(sMsg); 6}*4co
} 4%6@MQ[
BT f
Hdjp^O!
public static void log(int sMsg) \JP9lJ3<
{ -tp3qi
System.err.println(sMsg); T7(d
} "i!W(}x+
} C\ 34R
6HH:K0j3'
u5`b")a
/* %iZ~RTY6 !
**TestMethod.java qr~zTBT] E
*/ P75@Yu(
package NetFox; gmOP8.g
Ia:M+20n
<W*6=HZ'
public class TestMethod { C k/DV
WISK-z
~SXqhX-`
public TestMethod() \8k4v#wH
{ ///xx/weblogic60b2_win.exe C]3^:b+
try{ 5{-54mwo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &0+Ba[Z ^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d-I=xpB
SiteFileFetch fileFetch = new SiteFileFetch(bean); ifmX<'(9A
fileFetch.start(); *#GX~3A
} H8E#r*"-m
catch(Exception e){e.printStackTrace ();} _OK!/T*FBt
m5W':vM
%B\VY+
} W>[TFdH?
wid
eXkpU7w;
public static void main(String[] args) &-Q_%eM^
{ &7eN EA
new TestMethod(); 6?/f$,v
} =$_kkVQ$
} s|R`$+'{
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