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)); 0jTMZ<&zZ
} =|V"#3$f
for(int i=0;i<nEndPos.length-1;i++) e&Rb
{ 4J8Dh;a`
nEndPos = nStartPos[i+1]; 4J}3,+
} !.eAOuq
nEndPos[nEndPos.length-1] = nFileLength; "TFwHe3C4
} wY`#$)O0*
} V16%Ne
61,O%lV
O6]u!NqG
//启动子线程 PbN3;c3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {AgBwBCE
for(int i=0;i<nStartPos.length;i++) ,qu:<
{ s41adw>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]-Lruq#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mn`5pha
nStartPos,nEndPos,i); y5%5O xB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m1y `v"
fileSplitterFetch.start(); mATH*[Y
} 5rN7':(H!%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?i%nMlcc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b9#m m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AY;<q$8j%,
nEndPos = " + nFileLength); zq=&4afOE
// fileSplitterFetch[nPos.length-1].start(); t= *Jg/$
Hz?,#>{
Tzf$*Uje3
//等待子线程结束 qK-qcPLsl
//int count = 0; %omu
//是否结束while循环 |D+p$^L
boolean breakWhile = false; AysL-sqR
R8ZD#,;
D6:DrA:
while(!bStop) )Y8qWJU
{ ?FDJqJM
write_nPos(); c/RT0xql*
Utility.sleep(500); eA&t%
breakWhile = true; Gym#b{#":
ZQ|gt*
t%HI1eO7h
for(int i=0;i<nStartPos.length;i++) z L8J`W
{ kyu2)L2u
if(!fileSplitterFetch.bDownOver) !mae^A1
{ B,MQ.|s[
breakWhile = false; q|Fjm]AF
break; C(U
} AoU_;B\b%
} q#m!/wod
if(breakWhile) J@gm@ jLc
break; K4Y'B o4
$E@ouX?
0<3E
//count++; AHWh}~Yi
//if(count>4) p9Z].5Pd"
// siteStop(); BjB&[5?z
} ,3k@L\$.x
0}D-KvjyP
HoL~j({
System.err.println("文件下载结束！"); y:C)%cv}*
} T;J7+0
catch(Exception e){e.printStackTrace ();} $)f"K
} l-cW;b~
!YY6o V
3l$E8?[Zwi
//获得文件长度 C$t.C rxx
public long getFileSize() 9u?Eb~#$
{ 3? };
int nFileLength = -1; X'xUwT|_+
try{ n_1jHJo
URL url = new URL(siteInfoBean.getSSiteURL()); @wMQC\Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @Jm.HST#S8
httpConnection.setRequestProperty("User-Agent","NetFox"); L7<+LA)s0
_tA7=*@8
%6N)G!P
int responseCode=httpConnection.getResponseCode(); S7Znz@
if(responseCode>=400) blUY.{NN3
{ l\_x(BH
processErrorCode(responseCode); m^'~&!ba
return -2; //-2 represent access is error :q(D(mK
} 5 >'66gZ
]I8]mUiUH
NtqFnxm/
String sHeader; &jt02+Hj'
27Cz1[oX
:Jm!=U%'Z
for(int i=1;;i++) 3Fgz)*Gu]
{ ?P%|P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %n4@[fG%K
//Utility.log(in.readLine()); &{BBxv)y
sHeader=httpConnection.getHeaderFieldKey(i); ?THa5%8f
if(sHeader!=null) >n1h^AW
{ We\KDU\n
if(sHeader.equals("Content-Length")) #jOOsfH|k
{ 40R"^*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \|blRm;
break; 28ja-1dB
} gU~ L@R_D
} >CH
else "oHp.$+K
break; '^e0Ud,
} hI*`>9l
} QjI#Cs}w
catch(IOException e){e.printStackTrace ();} b/z'`?[
catch(Exception e){e.printStackTrace ();} l},dQ4R
ijE<spG
Wux0RF&
Utility.log(nFileLength); lK "'nLL
:,jPNuOA
9U&~(;
return nFileLength; o1Ne+Jt
} =[s8q2V
ix:2Z-
33*^($bE&
//保存下载信息（文件指针位置） EN)YoVk
private void write_nPos() mlD%d!.
{ $|rCrak;
try{ qI(W$
output = new DataOutputStream(new FileOutputStream(tmpFile)); *+NGi(N
output.writeInt(nStartPos.length); eR7qE) h
for(int i=0;i<nStartPos.length;i++) AbL5 !'
{ m\_+)eI|
// output.writeLong(nPos); L7X7Zt8%
output.writeLong(fileSplitterFetch.nStartPos); 3(MoXA*
output.writeLong(fileSplitterFetch.nEndPos); >ze>Xr'm5=
} $K`_ K#A
output.close(); 4A;[sm^f
} Yd[U
catch(IOException e){e.printStackTrace ();} 3(aRs?/O
catch(Exception e){e.printStackTrace ();} u.$Ym
} D% oueW
,<7"K&
<_=JMA5
//读取保存的下载信息（文件指针位置） G}182"#4
private void read_nPos() KrJ5"1=
{ #c6ui0E%;t
try{ lq~GcM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B.V?s,U
int nCount = input.readInt(); >s;oOo+5
nStartPos = new long[nCount]; izXbp02
nEndPos = new long[nCount]; Vp|2wlFE-
for(int i=0;i<nStartPos.length;i++) JtSuD>H`"
{ r;c' NqP
nStartPos = input.readLong(); W^^K0yn`@
nEndPos = input.readLong(); DxE(9j
} ,?C|.5
input.close(); &/ \O2Aw8
} h1n*WQ-
catch(IOException e){e.printStackTrace ();} &\JK%X.Jlt
catch(Exception e){e.printStackTrace ();} /TzNdIv
} %=laY_y G
976E3u"Vt
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private void processErrorCode(int nErrorCode) mk#>Dpy?
{ r3n=<l!Jr
System.err.println("Error Code : " + nErrorCode); UAnB=L,.\
} fx]\)0n
~C%2t{"
f+*J ue
//停止文件下载 7bctx_W&6
public void siteStop() QIR4<]/
{ Su$18a"Bc
bStop = true; _Ngx$
for(int i=0;i<nStartPos.length;i++) >.a+:
fileSplitterFetch.splitterStop(); <ED8"~_
O]c=Yyl
co \[{}}
} "2*G$\
} qXXYF>Z-
//负责部分文件的抓取 CkmlqqUHC
**FileSplitterFetch.java 1_N~1Ik
*/ JQ~y- lt
package NetFox; OAmES;Ck$(
m\<<oIlH
l0qdk#v
import java.io.*; pYYqGv^oa
import java.net.*; AM>Yj
ck(CA(_
<f7?PAd
public class FileSplitterFetch extends Thread { <9Lv4`]GU5
bRx2 c
?|D$#{^
String sURL; //File URL \pjRv
long nStartPos; //File Snippet Start Position hubfK~
long nEndPos; //File Snippet End Position 9V|E1-")E
int nThreadID; //Thread's ID 1~["{u
boolean bDownOver = false; //Downing is over | \ s2
boolean bStop = false; //Stop identical &p/S>qKu#
FileAccessI fileAccessI = null; //File Access interface :iP>z}h
|pfhrwJp
M'pb8jf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2#>$%[
{ ..vSL
this.sURL = sURL; o?:;8]sr!
this.nStartPos = nStart; ;X?Ah
this.nEndPos = nEnd; `,F&y{A
nThreadID = id; u5xU)l3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >wz;}9v
} y#hga5
<_##YSGh,
}"F ?H:\
public void run() 4yA9Ni
{ ?b!CV
while(nStartPos < nEndPos && !bStop) ti$oZ4PpF
{ N&6_8=3z
b@nri5noBm
8@Egy%_
try{ jF%)Bhn(
URL url = new URL(sURL); r Iya\z1W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /e-ka{WS
httpConnection.setRequestProperty("User-Agent","NetFox"); zjluX\
String sProperty = "bytes="+nStartPos+"-"; Z!C`f/h9
httpConnection.setRequestProperty("RANGE",sProperty); $nUd\B$.=
Utility.log(sProperty); 6{JR0
"#mXsp-ut
*u|lmALs
InputStream input = httpConnection.getInputStream(); r;&]?9)W0
//logResponseHead(httpConnection); -mev%lV
c!'A)JD@
Ze[g0"
byte[] b = new byte[1024]; Y9IJ
int nRead; Cm,*bgX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "D ts*
{ Wrf^O2
nStartPos += fileAccessI.write(b,0,nRead); _&k'j)rg
//if(nThreadID == 1) 7Y-FUZ.`>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &+)+5z_d
} p9FA_(`^
uE,i-g0$Id
blKDQ~T2
Utility.log("Thread " + nThreadID + " is over!"); N0y;PVAGu
bDownOver = true; J6@(X8w{j
//nPos = fileAccessI.write (b,0,nRead); ^4xlZouCb
} &&(4n?
catch(Exception e){e.printStackTrace ();} %Y)PH-z
} 5 {T9*
} EIq{C-(
Ze$^UR
SQO>}#qm
//打印回应的头信息 Bi9 N
public void logResponseHead(HttpURLConnection con) { 4_I7r
{ d-6sC@PB
for(int i=1;;i++) 2ru*#Z#(
{ aGq_hP
String header=con.getHeaderFieldKey(i); B)j`}7O06
if(header!=null) ]Ks]B2Osz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B$}wF<`k7
Utility.log(header+" : "+con.getHeaderField(header)); 8! |.H p
else EmtDrx4!(f
break; U~u6}s]:
} dCf'\@<<
} ZYwBw:y}y
%5Q7#xU
i#pjv'C
public void splitterStop() Mr5('9%
{ WL IDw@fv
bStop = true; bm|Jb"T0b
} Nt`F0 9S
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} )#b}qc#`
mJ6t.%'d
PTuCN
/* N3XVT{yo
**FileAccess.java S7?f5ux
*//文件访问(定位，写) O+(. 29
package NetFox; p"hm.=,
import java.io.*; ++J Bbuzj!
.XV]<)<K$
;X*K*q
public class FileAccessI implements Serializable{ zumR(<l
'mBLf&fB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OEy:#9<'
RandomAccessFile oSavedFile; "xvV'&lQ
long nPos; sUyCAKebRr
2-"Lxe65f
3oppV_^JdT
public FileAccessI() throws IOException /ctaAQDUh\
{ |?;"B:0
this("",0); ohQz%?r
} YO.`l~ v
K%[}[.cW
1}n)J6m
public FileAccessI(String sName,long nPos) throws IOException %T&&x2p^=?
{ uJ|5Ve
oSavedFile = new RandomAccessFile(sName,"rw"); IEIxjek
this.nPos = nPos; P\*2c*,W;
oSavedFile.seek(nPos); W G3mQ\k
} dN$D6*
3&a*]
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public synchronized int write(byte[] b,int nStart,int nLen) n3HCd-z
{ *hk{q/*Qw
int n = -1; k2_6<v Z
try{ MQ9M%>
oSavedFile.write(b,nStart,nLen); @mQ/WYs
n = nLen; ?FY@fO?es
} bOdsMlJkN
catch(IOException e) 3IU$
{ yO$r'9?,*
e.printStackTrace (); VuO)
} HonAK
"EOk^1,y
eSvc/CU
return n; 2kp|zX(
} :uT fhr
T_(e(5
.=b +O~
} #RLch
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%WJ{IXlz
/* bY"eC i{K
**SiteInfoBean.java Ol/2%UJXL
*/ AT8B!m
package NetFox; xyz\;3
lvz:UWo
72s$
public class SiteInfoBean { %Zl_{Q]h
%b>y
X."h Tha5
private String sSiteURL; //Site's URL dp//p)B>
private String sFilePath; //Saved File's Path psyH?&T
private String sFileName; //Saved File's Name eHnei F
private int nSplitter; //Count of Splited Downloading File ]mD=Br*r~
8ZNd|\
e$/Zb`k
public SiteInfoBean() qN`]*baS
{//nSplitter的缺省值为5 x%:>Ol
//default value of nSplitter is 5 !cFE^VM_;
this("","","",5); tI!R5q;k
} bb O;AiHD
soQv?4
!Lg}q!*%>V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w=P<4bdT
{ {6=H/g=:i
sSiteURL= sURL; MeK\eZ\
sFilePath = sPath; 9/X v&<Tn
sFileName = sName; fbx;-He!
this.nSplitter = nSpiltter; +}G>M=t::
k.? T.9
&' Nk2{
} $CQwBsYb=
EbwZZSds1
(PT?h>|St
public String getSSiteURL() g6a3MJV`
{ c J"]yG)=
return sSiteURL; d,Dg"Z
} Z#cU#)`y1
7"CH\*%
~RR_[t2Z
public void setSSiteURL(String value) EH!EyNNb
{ =VX<eV
sSiteURL = value; @=zBF'<.9
} }~\].I6
;uA_gn!
B,VSFpPx
public String getSFilePath() {;z L[AgCg
{ h>5~ (n8
return sFilePath; B|q3;P
} !,(bXa\^
dXK~ Z:
W%jX-
public void setSFilePath(String value) 4Igs\x{i
{ 5Ret,~Vs9|
sFilePath = value; RWh}?vs_
} W!Ct[t
y3o4%K8
M3ZJt'|
public String getSFileName() ?=@Q12R)X
{ aab4c^Ms=
return sFileName; :PjUl
} G'}_ZUy#
&LxzAL,3!
/jL{JF>I
public void setSFileName(String value) RVKaqJ0e<
{ ^%OH}Z`ly
sFileName = value; K/.hJ
} 7rDRu]
PA-0FlV|
g7Q*KA+
public int getNSplitter() *ej o6>
{ _ L:w;Oy9T
return nSplitter; my\oC^/9
} Z FrXw+
+uGP(ONY
d<cbp[3F
public void setNSplitter(int nCount) fN%5D z-e
{ *1$~CC7
nSplitter = nCount; .LTFa.jxA
} hpi_0lMkI
} <n~g+ps
!VZCM{
ZwrYss
/* NwuBe:"@
**Utility.java xg5@;p
*/ au}0PnA;
package NetFox; u$/2XO
ib=^tK
fF]&{b~wk
public class Utility { Gt%?[
vFvu8*0
C%7)sLWjJS
public Utility() OsSiBb,W79
{ >`V|`Zi ?
AkQFb2|ir
iuk8c.TAR
} mS;Q8Crh
r_<i*l.
//线程睡眠 \C\y'H5
public static void sleep(int nSecond) OuIW|gIu0
{ cz~11j#
try{ Ecl7=-y
Thread.sleep(nSecond); iwTBE]J
} BL^Hj
catch(Exception e) l#f]KLv4N_
{ 9d(v^T
e.printStackTrace (); <EN[s
} (2(;u1
} :;u]Y7
2<./HH*f
//日志 ;}9Ws6#XQs
public static void log(String sMsg) ^p%+rB.j[
{ jP6G.aiO
System.err.println(sMsg); zyn =Xv@p
} B-p5;h>
K>JU/(
hfa_M[#Q-
public static void log(int sMsg) ' g!_Flk
{ NP`ll0s
System.err.println(sMsg); en6AAr:U}
} {ZI6!zh'
} _Wsk3AP
tJfN6
bD[W~ku
/* hpes
**TestMethod.java O.f3 (e!
*/ Bq=](<>>
package NetFox; 4~MUc!
NW Qu-]P
x(6.W"-S
public class TestMethod { A/6nVn
zQ^[=siZ}
]`U?<9~Ob
public TestMethod() z#67rh{
{ ///xx/weblogic60b2_win.exe 7uH{UpslJ
try{ nE$ V<Co}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d"uM7PMs7x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 05zdy-Fb
SiteFileFetch fileFetch = new SiteFileFetch(bean); `.Q3s?1F
fileFetch.start(); 0#GwhB
} U.} =j'Us+
catch(Exception e){e.printStackTrace ();} yAkN2
?^GsR[-x
-+Ji~;b
} 5.UgJ/
J, U~.c
R.$Y1=U6
public static void main(String[] args) ^Iq.0E9_
{ Nxk'!:
new TestMethod(); .y/?~+N^
} j-\u_#kx%
} 2_DtzY:=
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