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)); W(#u^,$e[
} mz>GbImVD~
for(int i=0;i<nEndPos.length-1;i++) SH1S_EQ<
{ MlKSjKl" !
nEndPos = nStartPos[i+1]; VY#nSF`
} -){aBMOv3
nEndPos[nEndPos.length-1] = nFileLength; =&K8~
} 1m~-q4D)V
} TCWt3\
wU}%]FqtZ=
-I0J-~#
//启动子线程 ;T\+TZtI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?-v]+<$Y
for(int i=0;i<nStartPos.length;i++) N^Hj%5
{ ljP<WD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `R!%k]$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '< .gKo
nStartPos,nEndPos,i); <9dfbI)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H`bS::JI-
fileSplitterFetch.start(); ?hmuAgOtbh
} 4JO[yN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Nsf>b8O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vojXo|c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ur9L8EdC
nEndPos = " + nFileLength); B&+)s5hh
// fileSplitterFetch[nPos.length-1].start(); YD{Ppz
/lS5B6NU
V(5*Dn84
//等待子线程结束 mHyT1e
//int count = 0; s-801JpiJ
//是否结束while循环 po!bRk[4
boolean breakWhile = false; Y@y"bjK \
l`<1Y|
koa-sy)#L
while(!bStop) 8l l}"
{ dQs>=(|t
write_nPos(); WYN0,rv1:+
Utility.sleep(500); eH]9"^> o
breakWhile = true; \0veld
7G+E+A5o&
Kw7uUJR
for(int i=0;i<nStartPos.length;i++) -#Ys67,4N
{ v[<x>?iD_
if(!fileSplitterFetch.bDownOver) Q~f mVWq
{ SE$~Wbj?
breakWhile = false; M?_7*o]!
break; m-2!r*(zt
} o1Krp '*
} 8#nAs\^
if(breakWhile) TD sjNFe3
break; K!,9qH
5gSe=|we*p
Jsa]RA
//count++; ZmDM=qN
//if(count>4) 7?;ZE:
// siteStop(); c'INmc I|
} tIT/HG_o
Z*+y?5+L"P
&`IJ55Z-)
System.err.println("文件下载结束！"); &u!MI
} rI OKCL?
catch(Exception e){e.printStackTrace ();} SyI\ulmL
} )UtK9;@"
if?X^j0
PA*1]i#2M=
//获得文件长度 zZW5M^z8
public long getFileSize() +|--}iE5n
{ h0 Xc=nj
int nFileLength = -1; =q(?ALGc
try{ ,e^~(ITaq
URL url = new URL(siteInfoBean.getSSiteURL()); 8,IQ6Or|-2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )3WUyD*UZN
httpConnection.setRequestProperty("User-Agent","NetFox"); R7 rO7M!
6:q,JB@i
vm7ag 7@O
int responseCode=httpConnection.getResponseCode(); PXG@]$~3
if(responseCode>=400) o!lKP>
{ jwg*\HO,s
processErrorCode(responseCode); h$#PboLd
return -2; //-2 represent access is error K 6yD64
} :NL[NbQYt
*'*,mfk[
<MKXFV
String sHeader; !+z&] S3s
HV'M31m~q
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for(int i=1;;i++) }G "EdhSl
{ v 8EI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1gnLKfc
//Utility.log(in.readLine()); 1*e7NJ/.,
sHeader=httpConnection.getHeaderFieldKey(i); 9^8_^F
if(sHeader!=null) ->*~e~T
{ kxR!hA8wv4
if(sHeader.equals("Content-Length")) k8!:`jG
{ *&tTiv{^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N,Js8Z"
break; lvRTy|%[
} LM(r3sonb
} (+6N)9rj`/
else MJ$.ST
break; jZQ{XMF
} :*/g~y(fE
} /'zXb_R,$
catch(IOException e){e.printStackTrace ();} oVr:ZwkG3
catch(Exception e){e.printStackTrace ();} ^oYRBEIJH
505ejO|
@r^s70{}
Utility.log(nFileLength); P @J)S ?
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return nFileLength; ,:#h;4!VRF
} BnfuI
/bn$@Cy@
*8+HQ[[#
//保存下载信息（文件指针位置） DZ1.Bm0
private void write_nPos() *Z\AO'h=Z
{ #?`S+YN!q)
try{ u9(42jj[$U
output = new DataOutputStream(new FileOutputStream(tmpFile)); *7=`]w5k1
output.writeInt(nStartPos.length); ~N/a\%`
for(int i=0;i<nStartPos.length;i++) f~,Ml*Zp
{ "Ec9.#U/
// output.writeLong(nPos); #C'E'g0
output.writeLong(fileSplitterFetch.nStartPos); EM@EB<pRX
output.writeLong(fileSplitterFetch.nEndPos); h4=mGJpm
} ;at1|E*
output.close(); vRn]u57O
} ^O=G%de
catch(IOException e){e.printStackTrace ();} w ~"%&SNN
catch(Exception e){e.printStackTrace ();} BR-wL3x b
} XAi0lN{,
tSnsjd<6.
$-|$4lrS
//读取保存的下载信息（文件指针位置） }I MV@z B
private void read_nPos() 9~$E+m(
{ a#G3dY>
try{ _mk@1ft
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f`*VNB`
int nCount = input.readInt(); 4<vi@,s
nStartPos = new long[nCount]; FhPCFmmUT
nEndPos = new long[nCount]; @h_ bXo
for(int i=0;i<nStartPos.length;i++) SkC.A?
{ Vugb;5Vl
nStartPos = input.readLong(); DSWmQQ
nEndPos = input.readLong(); kma>'P`G
} fFoZ!H
input.close(); C@[U:\
} fP6.
catch(IOException e){e.printStackTrace ();} ?RIf0;G
catch(Exception e){e.printStackTrace ();} e2K9CE.O
} KK5_;<
00s)=A_
xtIF)M
private void processErrorCode(int nErrorCode) FzP1b_i
{ -j2y#aP
System.err.println("Error Code : " + nErrorCode); 6|{&7=1t
} |:Maa6(W
$TS97'$
kj.9\
//停止文件下载 pq\N2d
public void siteStop() D%LYQ
{ wr=KAsH<
bStop = true; BjsTHS&
for(int i=0;i<nStartPos.length;i++) ,Vo[mB
fileSplitterFetch.splitterStop(); I.(@#v7T
r b\t0tg
|Ldvfd
} r{84Y!k~*
} WRAL/
//负责部分文件的抓取 1X`,7B@pz
**FileSplitterFetch.java $o;c:Kh$$
*/ g oyQ',+
package NetFox; >dJ~
(fr=N5
_h1eW9q
import java.io.*; #`f{\
import java.net.*; h^qZi@L
:vx<m_
Q$ Dx:
public class FileSplitterFetch extends Thread { Z h9D^I
olA+B
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String sURL; //File URL R".$x{{
long nStartPos; //File Snippet Start Position -^(KGu&L&u
long nEndPos; //File Snippet End Position =au!rda
int nThreadID; //Thread's ID A+frKoi
boolean bDownOver = false; //Downing is over HB$?}V
boolean bStop = false; //Stop identical L<3+D
FileAccessI fileAccessI = null; //File Access interface rnQ_0d
a j$& 9][
dKC*QHU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NP.i,H
{ 6>;OVX
this.sURL = sURL; :ir3u
this.nStartPos = nStart; *)`PY4zF
this.nEndPos = nEnd; &WL::gy_S
nThreadID = id; e57R6g)4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :dRC$?f4
} 9wGsHf8]
+]( y
)bL(\~0g~
public void run() aPK:k$.
{ >;Vfs{Z(q
while(nStartPos < nEndPos && !bStop) Njr;Wa.r+
{ Zlh 2qq
,Wu$@jD/]
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try{ {X{S[(|
URL url = new URL(sURL); s^IC]sW\%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x3#:C=
httpConnection.setRequestProperty("User-Agent","NetFox"); c2,g%(
String sProperty = "bytes="+nStartPos+"-"; }o7-3!{L!
httpConnection.setRequestProperty("RANGE",sProperty); j[FB*L1!D
Utility.log(sProperty); rPyjr(I"_
"\`Fu
1cMLl6Bp>
InputStream input = httpConnection.getInputStream(); ai1;v@1
//logResponseHead(httpConnection); 1%R${Qhr
M*D_pn&
%t!r pyD
byte[] b = new byte[1024]; |4P8N{ L>O
int nRead; 9&Un|cr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /wJ4hHY
{ $gz8! f?
nStartPos += fileAccessI.write(b,0,nRead); GD d'{qE6
//if(nThreadID == 1) LklE,W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z;2& d<h
} vO&X<5?Qc
+J;b3UE#
3`vKEThY)
Utility.log("Thread " + nThreadID + " is over!"); T,uF^%$@AQ
bDownOver = true; $joGda
//nPos = fileAccessI.write (b,0,nRead); ]3,
} -!qjBK,`X
catch(Exception e){e.printStackTrace ();} u9~Ncz
} F%&lM[N%
} @NL<v-t
<T)0I1S
`v)'(R7){
//打印回应的头信息 &v1E)/q{Z
public void logResponseHead(HttpURLConnection con) DbB<8$
{ HWB\}jcA6u
for(int i=1;;i++) 59SL mj
{ N%Y!{k5T7
String header=con.getHeaderFieldKey(i); !\d~9H%`B
if(header!=null) ,30lu a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :E|Jqi\
Utility.log(header+" : "+con.getHeaderField(header)); islHtX VE
else >R6mI
break; O;V^Fk(
} tWzBQx
} 2Og5e
ml^=y~J[
$M0l (htR
public void splitterStop() \?Z7|
{ QJVB:>A
bStop = true; v?6*n>R
} GYb&'#F~t
dqQJC qc!
N#RC;
} XRQ1Uh6
G4'Ee5(o
_%Xp2`m
/* 8rlf9m
**FileAccess.java DCLu^:|C"
*//文件访问(定位，写) <8? F\x@
package NetFox; jVOq/o
import java.io.*; L>g6 9D!
)CE]s)6+2
J1cz D|(
public class FileAccessI implements Serializable{ FW;}S9u3
:eD-'#@$u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L >"O[@
RandomAccessFile oSavedFile; ??P\v0E
long nPos; sKKc_H3YSH
3WwCo.q;m
tq~f9EvC
public FileAccessI() throws IOException yX{7<\x
{ M[O22wFs
this("",0); g{sp<w0
} ,?qJAV~>
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'-n Iy$>
public FileAccessI(String sName,long nPos) throws IOException AX6:*aZB
{ <3N\OV2
oSavedFile = new RandomAccessFile(sName,"rw"); ''q;yKpaz
this.nPos = nPos; e:4,rfF1
oSavedFile.seek(nPos); *\}$,/m['
} ht6}v<x.eA
/g9^g(
FYE(lEjxi
public synchronized int write(byte[] b,int nStart,int nLen) _99 +Vjy
{ t.RDS2N|
int n = -1; aQY.96yo
try{ }QQl.'
oSavedFile.write(b,nStart,nLen); *sB'D+-/
n = nLen; dxZn| Y
} Gl3g.`X{$@
catch(IOException e) (vi^ t{k
{ L[Y$ `e{zd
e.printStackTrace (); .=G3wox3
} QhRj*,
+8\?7,FY
%" mki>
return n; + `'wY?
} | a i#rU
}uaFmXy3
=s'H o
} 3xP<J)S0
?y>v"1+
wouk~>Jft
/* =u0a/2u|
**SiteInfoBean.java !H c6$
*/ ~p{YuW[e
package NetFox; ?/hS1yD;
uX{g4#eG
>,k2|m
public class SiteInfoBean { *>W6,F7
F2Ny=H&G
[4B(rra
private String sSiteURL; //Site's URL |d6/gSiF
private String sFilePath; //Saved File's Path 1g,gilc
private String sFileName; //Saved File's Name !{(crfXB
private int nSplitter; //Count of Splited Downloading File +gBDE:
a5pM~.]
o@j!JI&
public SiteInfoBean() F &5iA\
{//nSplitter的缺省值为5 Wie0r@5E
//default value of nSplitter is 5 QJR},nZ3
this("","","",5); J &=5h.G$
} /J!hKK^k
F`,bFQ
<.BY=z=H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HJ"sK5Q
{ "iK'O =M
sSiteURL= sURL; 0N4ZV}s,d
sFilePath = sPath; >k=@YLj
sFileName = sName; lY,9bSF$
this.nSplitter = nSpiltter; :AuKQ`c
OzRo
|@R/JGB^
} Ly v"2P
G$Fo*;Fl
TOSk+2P
public String getSSiteURL() l_+q a6C*
{ -H_#et3&i
return sSiteURL; I7'v;*
} &js$qgY
AtAu$"ue
_XrlCLp: d
public void setSSiteURL(String value) l#>A.-R*`
{ !>K=@9NC|.
sSiteURL = value; YxU->Wi]G
} NP~3!b
J]48th0,
9v ,y
public String getSFilePath() D`B*+
{ SwrzW'%A
return sFilePath; k4:=y9`R}$
} s6 K~I
-I#<?=0B
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public void setSFilePath(String value) gMZrtK`<
{ 76c:*bZ
sFilePath = value; S!JLy&@
} %/s+-j@s:
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6Ol)SQE,
public String getSFileName() ~1,$
{ w/(2fU(
return sFileName; />PH{ l
} ({C|(v9C7
O4a~(*f
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public void setSFileName(String value) su8()]|0x
{ d,j)JnY3V
sFileName = value; O#vIn}
} $V_w4!:Q
\C1`F[d_
&&96kg3
public int getNSplitter() |hu9)0P
{ r6 pz(rCs}
return nSplitter; nK]L0*s
} "!Hm.^1
ET6}V"UD
cI<T/~P
public void setNSplitter(int nCount) c&SSf_0O*
{ :pP l|"
nSplitter = nCount; GN|xd+O_
} 7V~ gqum
} s8r[U, }(
]XfROhgP=
79'N/:.
/* yfAh=
**Utility.java 8&#)}A}x
*/ h~&5;
package NetFox; >T29kgF2
%b ^.Gw\L
$*+UX
public class Utility { ;@[ax{ J
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public Utility() Iw</X}#\
{ t@BhosR-
m&6)Vt
U {sT %G
} Aq&H-g]s
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//线程睡眠 6 &MATMR
public static void sleep(int nSecond) mH4Jl1S&
{ thQ)J|1
try{ j"P}Wn
Thread.sleep(nSecond); p=f8A71
} "nn>I}jK
catch(Exception e) ]y/!GFQ
{ tWI4x3&2
e.printStackTrace (); 3Ett9fBd
} "3uPK$
} 1Qo2Z;h@
d@<~u,Mt&F
//日志 !}&f2!?.W
public static void log(String sMsg) inv 5>OeG
{ xz vbjS W
System.err.println(sMsg); tc)4$"9)
} dWDf(SS
7@9R^,M4:
!XrnD#
public static void log(int sMsg) DzK%$#{<
{ >^+c s^jCM
System.err.println(sMsg); 7T9Mo .
} :|E-Dx4F6H
} (n~GKcA
#p|7\Y
PQ`~qM:3st
/* v.e~m2u_F
**TestMethod.java 8j&LU,
*/ ZNTOI]P&
package NetFox; ADVHi3b
TmO3hKaP
R"k}wRnxY
public class TestMethod { ]tDuCZA
*lws7R
V|zatMHs
public TestMethod() lG!We'?
{ ///xx/weblogic60b2_win.exe LuUfdzH
try{ zD}2Zh]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *Z=:?4u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IAa}F!6Q1
SiteFileFetch fileFetch = new SiteFileFetch(bean); zXx)xIO
fileFetch.start(); j692M.A
} |dQ-l !
catch(Exception e){e.printStackTrace ();} x5)YZ~5
)M(-EDL>Qk
B&k"B?9mL
} j@+QwZL|
BD (
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public static void main(String[] args) Y)]x1I
{ ley:=(
new TestMethod(); CHX- 4-84{
} v08Xe*gNU
} )=c/{
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