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)); X/AA8QV o
} IEj=pI
for(int i=0;i<nEndPos.length-1;i++) ,b${3*PPQ
{ n&fV^ x
nEndPos = nStartPos[i+1]; <&m `)FJ
} HUWCCVn&
nEndPos[nEndPos.length-1] = nFileLength; +cf.In,{
} <8sy*A?0z
} Su>UXuNdE#
O_^X:0}
"raC?H
//启动子线程 z$]HZ#aRE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p6*|)}T_%
for(int i=0;i<nStartPos.length;i++) dk@j!-q^
{ .!2Ac
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \0bZ1"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mA" 82"
nStartPos,nEndPos,i); JANP_b:t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XJ*W7HD
fileSplitterFetch.start(); :ySQ[AJ"
} F7N4qq1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -guVl4 V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z5[f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %:=Jr#a
nEndPos = " + nFileLength); S!{Kn ;@
// fileSplitterFetch[nPos.length-1].start(); tLc~]G*\`s
jHx)q|2\
?S0gazZm
//等待子线程结束 y^tp^
//int count = 0; \?K>~{)
//是否结束while循环 5Vu@gRk_
boolean breakWhile = false; a"pejW`m
ffibS0aM
`7o(CcF6H
while(!bStop) k_A 9gj1
{ kFZjMchm A
write_nPos(); .#wU+t>
Utility.sleep(500); Ng;Fhv+
breakWhile = true; ufc_m4PN
/sa\Ze;E
0Ik}\lcn
for(int i=0;i<nStartPos.length;i++) ndxijqw
{ =k|hH~
if(!fileSplitterFetch.bDownOver) y|O)i I/g
{ P;~P:qKd
breakWhile = false; Ag@R60#
break; d\{a&\v
} *s}j:fJ
} r<XlIi
if(breakWhile) I]B[H6
break; 0ofl,mXW
t^(#~hx
1Yb9ILX[J
//count++; |@lVFEl]
//if(count>4) $"`9QD~
// siteStop(); h6Q-+_5
} eK_Yt~dj
p}{V%!`_
!tr /$
System.err.println("文件下载结束！"); -mPrmapb3
} /`YbHYNF[
catch(Exception e){e.printStackTrace ();} 8C4=f
} O,A}p:Pgs
l0g`;BI_
wG2-,\:
//获得文件长度 Q{))+'s2h
public long getFileSize() 'h~I#S4!
{ EHC^ [5
int nFileLength = -1; #{L !o5
try{ `h+1u`FJ
URL url = new URL(siteInfoBean.getSSiteURL()); u,Rhm-`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vo-]&u&cr
httpConnection.setRequestProperty("User-Agent","NetFox"); 4}t&AW4
v*.#LJEm
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int responseCode=httpConnection.getResponseCode(); AG==A&d>$
if(responseCode>=400) W;9Jah.
{ %G>|u/:U
processErrorCode(responseCode); k3FpD=N
return -2; //-2 represent access is error x[i Et%_
} gbc])`aJ>
4 fxD$%9
?=lnYDj
String sHeader; ;N/=)m
}^/;8cfLY
-a(\(^NW
for(int i=1;;i++) Z<t(h=?
{ fqgm`4>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6opubI<
//Utility.log(in.readLine()); <0hJo=6a8
sHeader=httpConnection.getHeaderFieldKey(i); uY5Gn.Y
if(sHeader!=null) S.kFs{;1x
{ dPfDPb
if(sHeader.equals("Content-Length")) _-.~>C
{ !1M=9 ~$!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7L=V{,,v
break; e2xqKG
} bk#t+tuk
} }hjJt,m
else :/ yR
break; 4{1.[##]o
} ;PrL)!
} ^"Nsb&
catch(IOException e){e.printStackTrace ();} 1q[vNP=g&
catch(Exception e){e.printStackTrace ();} +^6v%z
:i24@V~){
Mi5"XQ>/
Utility.log(nFileLength); !Ci\Zg
ZdJer6:Z}
?-e'gC
return nFileLength; b@&ydgmaQ
} 43?J~}<Vs
+J~q:b.
XS'0fq a
//保存下载信息（文件指针位置） D(]])4
private void write_nPos() oQvG3(.
{ xedbr
try{ /N>bEr4w
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3C8W]yw/s
output.writeInt(nStartPos.length); t/baze;V
for(int i=0;i<nStartPos.length;i++) m )2t<
{ &Z^,-Y
// output.writeLong(nPos); {=NHidi~
output.writeLong(fileSplitterFetch.nStartPos); ,6%{9oW9Z:
output.writeLong(fileSplitterFetch.nEndPos); gl4|D
} Q3vWwP;t~
output.close(); %joIe w]V3
} 8;YN`S!o
catch(IOException e){e.printStackTrace ();} vkXdKL(q
catch(Exception e){e.printStackTrace ();} Hkv4t5F
} zJfoU*G/B
TZ7{cekQ
t: =
//读取保存的下载信息（文件指针位置） Q.Kr;64G
private void read_nPos() srN>pO8u~
{ S>]Jc$
try{ cXJtNW@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3psCV=/z
int nCount = input.readInt(); &!3=eVg
nStartPos = new long[nCount]; FH'jP`
nEndPos = new long[nCount]; N>fC"
for(int i=0;i<nStartPos.length;i++) Cz\(.MWNZ
{ $UZ4,S?V
nStartPos = input.readLong(); 35;)O -
nEndPos = input.readLong(); gJVakR&
} T1y,L<7?
input.close(); "}bk *2
} $o"PQ!z
catch(IOException e){e.printStackTrace ();} ^;2dZgJ4^
catch(Exception e){e.printStackTrace ();} <N%8"o
} \Mv8pU
o%Lk6QA$
Z:#-4CiP
private void processErrorCode(int nErrorCode) H>-?/H
{ C/Ig.KmXF{
System.err.println("Error Code : " + nErrorCode); ({cgak
} :zC'jceO
m<BL/7
_[SP*" ]H
//停止文件下载 N.q4Ar[x#p
public void siteStop() 1:%m >4U
{ <[^nD>t_
bStop = true; d0b--v/
for(int i=0;i<nStartPos.length;i++) 2O|o%`?
fileSplitterFetch.splitterStop(); FxKb
)>ed6A1
[|2uu."$
} @NXGVmY1}
} $J#}3;a
//负责部分文件的抓取 \<VwGbzFi
**FileSplitterFetch.java ?S8cl7;+
*/ Y962rZ
package NetFox; DU7kZ
RGGP6SDc
&50Kn[
import java.io.*; )S$!36Ni[
import java.net.*; E0c5c
}TRr*] P<%
W|T"'M_
public class FileSplitterFetch extends Thread { .ukP)rGe
H{x}gBQ
0>-l {4srs
String sURL; //File URL l%"eQ
long nStartPos; //File Snippet Start Position `}F=Zjy
long nEndPos; //File Snippet End Position twx8TQ9
int nThreadID; //Thread's ID ij6ME6
boolean bDownOver = false; //Downing is over Y.yM1 z
boolean bStop = false; //Stop identical (J): >\a]
FileAccessI fileAccessI = null; //File Access interface BNg\;2r
!&C8y
oJ`ih&Q8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `"m"qUd
{ gv;=Yhw.c
this.sURL = sURL; ?x@BZe
this.nStartPos = nStart; ~?aq=T
this.nEndPos = nEnd; M~7?m/Wj
nThreadID = id; 3Fh<%<=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :*1Gs,
} `4Z#/g
DRi!WWivn
muo7KUT
public void run() 1uv"5`%s
{ hE!3kaS
while(nStartPos < nEndPos && !bStop) doXd6q4H
{ E8>npDFv.
3l>P>[<o
IqEY.2KN
try{ Tm_vo-
URL url = new URL(sURL); f9D7T|J?10
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \+v_6F
httpConnection.setRequestProperty("User-Agent","NetFox"); b0E(tPw5c
String sProperty = "bytes="+nStartPos+"-"; "twV3R
httpConnection.setRequestProperty("RANGE",sProperty); @?K(+BGi
Utility.log(sProperty); >}<:5gZtA
7%8,*T
-z0,IYG }
InputStream input = httpConnection.getInputStream(); [j}%&$
//logResponseHead(httpConnection); P _Zf(`jJ
vsoj] R$C
gSu+]N
byte[] b = new byte[1024]; .gT@_.ZD9
int nRead; 8&ZUkDGkJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pZGso
{ 5cyl:1Ln
nStartPos += fileAccessI.write(b,0,nRead); .4F(Y_c
//if(nThreadID == 1) t2+m7*76
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nI.#A
} rN{&$+"2
#>~$`Sg
h&yaug,.
Utility.log("Thread " + nThreadID + " is over!"); Y*f7& '[
bDownOver = true; >K-O2dry*
//nPos = fileAccessI.write (b,0,nRead); %9BC%w]y
} C-_u; NEu
catch(Exception e){e.printStackTrace ();} #B'WT{B$/~
} 6!g3Juh
} &66G
V85a{OBm,8
KfWVz*DC!
//打印回应的头信息 |fTQ\q]W
public void logResponseHead(HttpURLConnection con) r9s1\7]x
{ V}9wx%v
for(int i=1;;i++) 4_t aCK
{ Z/;rM8[{&
String header=con.getHeaderFieldKey(i); wC=IN
if(header!=null) -mX _I{BJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i>,5b1x~
Utility.log(header+" : "+con.getHeaderField(header)); ]pb;q(?^
else kf-ZE$S4
break; ,[Cl'B
} D9H|]W~
} )zUV6U7v
`?=AgGg
+-ieaF
public void splitterStop() {Fb)Z"8]
{ 348Bu7':
bStop = true; ,Z>RvLl
} $!obpZ~}
T X6Ydd
W11_MTIU
} >454Yir0Mk
RNX}Wlo-s
%Si3t2W/
/* \3)%p('
**FileAccess.java gdCU1D\
*//文件访问(定位，写) VIi|:k
package NetFox; Z"!C
import java.io.*; k92X)/ll'
SC|cCK hqi
Uut,cQ". d
public class FileAccessI implements Serializable{ 0^["&K/
RE"}+D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -'q=oTZ
RandomAccessFile oSavedFile; $yCj80m\
long nPos; S~6<'N&[
UBC[5E$
^@[[,1"K
public FileAccessI() throws IOException lc5NC;JR
{ e2B~j3-?z
this("",0); z>y,}#D?C
} u5R^++
(V=lK6WQm
*VRFs=
public FileAccessI(String sName,long nPos) throws IOException orHVL2 KK
{ Vn8Qsf1f
oSavedFile = new RandomAccessFile(sName,"rw"); z6{0\#'K
this.nPos = nPos; >T!n* -Zn
oSavedFile.seek(nPos); {L4^IKI
} P_ZguNH
'Ob5l:
k8*=1kl"
public synchronized int write(byte[] b,int nStart,int nLen) C)ChF`Ru':
{ w[|!$J?
int n = -1; 1m![;Pg3
try{ 'GW@P
oSavedFile.write(b,nStart,nLen); #x%O0
n = nLen; {UPIdQ'g
} HQUL?URt
catch(IOException e) KR522YW
{ Wq>j;\3b3
e.printStackTrace (); qmL!"ZRLF
} uox;PDK
fO(.I
foJ|Q\Z,T
return n; K1+,y1c
} #Ta@A~.L
75v*&-
`\.n_nM
} P)}:lTe
j?8E >tM
] 2b@mX
/* C]):+F<7
**SiteInfoBean.java Icr'l$PE
*/ -u9{R\S
package NetFox; h|-r t15
ev@1+7(
)8N/t6Q
public class SiteInfoBean { @?%"nK
5GRN1Aov<
nC*/?y*9
private String sSiteURL; //Site's URL z1:auodI@
private String sFilePath; //Saved File's Path O'mX7rY<<(
private String sFileName; //Saved File's Name IM@Qe|5
private int nSplitter; //Count of Splited Downloading File LvAIAknc
x)GoxH~#
I7Eg$J&
public SiteInfoBean() ahf$#UQLb
{//nSplitter的缺省值为5 9GGBJTk-
//default value of nSplitter is 5 5_i&}c23Vn
this("","","",5); r%a$u%)oD
} xGH%4J\
3NJH"amk
5&xvY.!27V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7u}r^+6_o
{ XH*^#c
sSiteURL= sURL; 0GG;o[<
sFilePath = sPath; x Dr^&rC
sFileName = sName; EgO4:8$h
this.nSplitter = nSpiltter; o^NQ]BdH8
rms&U)?
[AGm%o=)
} REsThB
" DFg"
R.fRQ>rI
public String getSSiteURL() &=UzF
{ lWdE^-
return sSiteURL; yZ P+
} :L?zk"0C
4 IHl'*D[#
vSyN_AB?$
public void setSSiteURL(String value) ae<KUThm.
{ &0lNj@/
sSiteURL = value; q\/|nZO4
} /bb4nM_E/
Jv?e?U
B\mdOTLQ
public String getSFilePath() o60wB-y
{ mB,7YZv
return sFilePath; nxJhK T
} Vy?w,E0^:
,yT4(cMBk?
WGO=@jkf
public void setSFilePath(String value) WV6vM()#!C
{ C$hsR&
sFilePath = value; <FJ#Hy+
} qzLRA.#f^
X}Csl~W8in
(0][hdI~B
public String getSFileName() oT_,k}LIX
{ OW.ckYt%
return sFileName; l nZ=< T
} HOw][}M_w
[Cs2H8=#
}FK6o 6
public void setSFileName(String value) 'D-imLV<<
{ UO&S6M]v7
sFileName = value; Ff,M~zn
} b)V[d8IA
x}roPhZ
<E^:{J95
public int getNSplitter() Gg&jb=
{ dfrq8n]
return nSplitter; x88$#N>Q5
} fT@#S}t
%d>Ktf
87HVD Di
public void setNSplitter(int nCount) !At_^hSqz
{ s9Xeh"
nSplitter = nCount; wF%XM_M
} Wb|IWnH$
} vxwctJ&
7e40 }n
Rub""Ga
/* /M#A[tZ3
**Utility.java [$V_qFv{
*/ "16==tLFE
package NetFox; F;z FKvn
u'N'<(\k
D8h~?phK
public class Utility { "_(o% \"7
n,0}K+}
l"MEX/
public Utility() Z^h4%o-l{
{ 9M7{.XR,
nyMA%9,B
2L,e\]2Z
} @z2RMEC~
0nl)0|?Az
//线程睡眠 l&C%oW
public static void sleep(int nSecond) [pOU!9v4
{ Z|~<B4#c
try{ p%G\5.GcJL
Thread.sleep(nSecond); SKYS6b
} G?[#<W@+
catch(Exception e) plp).Gq
{ oACE:h9U
e.printStackTrace (); ?5->F/f&
} S>'wb{jj!
} i%z}8GIt'
<( MBs$b
//日志 ly{~X
public static void log(String sMsg) .AV--oA~
{ hZ%Ie%~n
System.err.println(sMsg); f[%iRfUFw
} v=/V<3
aEgzQono
HL_MuyE
public static void log(int sMsg) %fxGdzu7.
{ @c&)K^v8
System.err.println(sMsg); TM"i9a? ;
} jOe %_R
} 1~_]"Y'
]{;K|rCR-
Y[pGaiN:
/* lk+)-J-lj'
**TestMethod.java 2 OGg`1XX
*/ LxG :?=O.
package NetFox; O[8Lp?
Pl 5+Oo
Bg34YmZ
public class TestMethod { A]>0lB
j7i[z>:Y
TeG'cKz
public TestMethod() mDo]5 i<
{ ///xx/weblogic60b2_win.exe jIEK[vJ`
try{ ()P?fed
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VGe/;&1h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &yYK%~}t[
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'av OQj]`K
fileFetch.start(); HeR-;L
} o{:D
catch(Exception e){e.printStackTrace ();} 6KV&E8Gn
9WHkw@<R+
X3q'x}{
} }G-qOt
psYfz)1;
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public static void main(String[] args) /LJ?JwAvg5
{ bk"` hq
new TestMethod(); -BB5bsjA
} :JPI#zZun
} rs!J<CRq
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