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)); 3Z%jx#
} WxtB:7J
for(int i=0;i<nEndPos.length-1;i++) RTL@WI
{ WtMDHfwqu\
nEndPos = nStartPos[i+1]; d#I; e
} 8Urj;KkD
nEndPos[nEndPos.length-1] = nFileLength; S;nlC
} ^Uik{x
} DM(c :+K-
^X:g C9
sHSg _/|
//启动子线程 5hlS2fn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N_VWA.JHt
for(int i=0;i<nStartPos.length;i++) -e*(+
{ - KaU@t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cA!o xti
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '^,|8A2
nStartPos,nEndPos,i); uC 2{ Mmy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0qN+W&H
fileSplitterFetch.start(); rp!{QG
} |W|RX3D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D}nRH@<`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ( D@U%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Qf}}/k|)k
nEndPos = " + nFileLength); TM,Fab &
// fileSplitterFetch[nPos.length-1].start(); QnIF{TS=
e:|Bn>*
):5H,B+Vr&
//等待子线程结束 zf[KZ\6H
//int count = 0; ]%h|ox0
//是否结束while循环 LJ*W&y(2>Q
boolean breakWhile = false; uCf _O~
*p^*>~i9)
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while(!bStop) /nNrvMtv
{ ;n/04z
write_nPos(); )zo:Bo .<
Utility.sleep(500); 6>Is-/hsy
breakWhile = true; 9aY}+hgb#
'L veCi_
f;,^ ]mw
for(int i=0;i<nStartPos.length;i++) hx;0h&L
{ L#u!T)!zW
if(!fileSplitterFetch.bDownOver) H\=S_b1wo
{ -JXCO<~k
breakWhile = false; GbBz;ZV%z,
break; 2P?|'U
} 5 r&n
} a,?u 2
if(breakWhile) \7*"M y*
break; qW9~S0sl
XchVsA
j\uPOn8k
//count++; >s>{+6e
//if(count>4) dpB\=
// siteStop(); x I(X+d``
} Y;>D"C..
PO]c&}/
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System.err.println("文件下载结束！"); <;zcz[~
} dZ,~yV
catch(Exception e){e.printStackTrace ();} tP|ox]
} -D^v:aC
%j;mDR95
!<4=@
//获得文件长度 SG-Xgr@
public long getFileSize() h`V#)Q
{ RhSoD.Da
int nFileLength = -1; [?VkwFD0
try{ =_vW7-H
URL url = new URL(siteInfoBean.getSSiteURL()); M}N[> ,2'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3;wOA4ur
httpConnection.setRequestProperty("User-Agent","NetFox"); bA(-7l?
Q=F4ZrNqD
^wb$wtL('
int responseCode=httpConnection.getResponseCode(); Q>l5:2lq
if(responseCode>=400) G"F:68
{ &z;1Z
processErrorCode(responseCode); }x?2txuu
return -2; //-2 represent access is error =~'{2gsB
} o=I.i>c
q#P@,|nc:
&u9@FFBT8
String sHeader; n~?n+\.&a
*ZV=4[#bT
+o}mV.&1,
for(int i=1;;i++) _{y4N0
{ e<HHgC#J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'EkuCL
//Utility.log(in.readLine()); >1NE6T
sHeader=httpConnection.getHeaderFieldKey(i); :lp V
if(sHeader!=null) p!H'JNG
{ `fq#W#Pu
if(sHeader.equals("Content-Length")) '\/|K
{ L(_bf/@3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ac#I$V-
break; Pfl8x
} ,g{Ob{qT
} ^,6c9Dxy
else j@Y'>3
break; +YCKd3/
} yFjjpEpnFt
} |HA1.Y=
catch(IOException e){e.printStackTrace ();} ,2Q5'!o
catch(Exception e){e.printStackTrace ();} |)b:@q3k+n
lD@`xq.M;
HkdBPMs79
Utility.log(nFileLength); ko`.nSZ-k
)wfqGkr=m!
C0 o
return nFileLength; 2~)r,.,
} )]3_o!o
,p9>/)l
!9vq"J~hz"
//保存下载信息（文件指针位置） C=<PYkt,L
private void write_nPos() [^eQGv[S
{ T6I$7F
try{ zF#:Uc`C5U
output = new DataOutputStream(new FileOutputStream(tmpFile)); SuFGIb7E
output.writeInt(nStartPos.length); ,!oR"b!
for(int i=0;i<nStartPos.length;i++) V D.T=(
{ fW3NH7aUG
// output.writeLong(nPos); aW;DfH
output.writeLong(fileSplitterFetch.nStartPos); N2$uw@s
output.writeLong(fileSplitterFetch.nEndPos); @agxu-Y
} KU*XRZu)
output.close(); 9;`E,w
} <@J0 770
catch(IOException e){e.printStackTrace ();} ECr}7R%
catch(Exception e){e.printStackTrace ();} xpB*>zb
} HAdDr!/`
V~"-\@
ID8u&:
//读取保存的下载信息（文件指针位置） U\x$@J
private void read_nPos() 2su/I
{ WADAp\&
try{ 4)NbQ[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {&0u:
int nCount = input.readInt(); Vl%UT@D|
nStartPos = new long[nCount]; (u-eL#@
nEndPos = new long[nCount]; V[ 'lB.&t
for(int i=0;i<nStartPos.length;i++) eizni\
{ n+SHkrW
nStartPos = input.readLong(); -wQ@z6R
nEndPos = input.readLong(); cE+Y#jB
} /SD(g@G,
input.close(); u{%dm5
} BY`vs+]XY
catch(IOException e){e.printStackTrace ();} *dPG[ }
catch(Exception e){e.printStackTrace ();} QHgkfo
} f yhBfA:u
[SU;U['7
qw6i|JM%
private void processErrorCode(int nErrorCode) _DLELcH Y
{ [K""6D
System.err.println("Error Code : " + nErrorCode); pI1IDu*_Z
} s|!lw
1Ms_2
jAak,[~;
//停止文件下载 *IWWD\U
public void siteStop() 1w'W)x
{ FqXE6^
bStop = true; k\KI#.>
for(int i=0;i<nStartPos.length;i++) +D d!
fileSplitterFetch.splitterStop(); A&D<}y/%
/|>?!;
6d/1PGB
} sMgRpem;
} O 4'/C]B2
//负责部分文件的抓取 Ox9M![fC
**FileSplitterFetch.java UOn:@Qn
*/ !Wz4BBU8o
package NetFox; `CY c>n"
WYd9p;k
dry>TXG*
import java.io.*; "X \Yp_g
import java.net.*; UT_kw}1o
,ut7`_Fy
#MUY!
public class FileSplitterFetch extends Thread { : 22)` ;0
K8RV=3MBLD
l-$5CO
String sURL; //File URL =B0AG9Fz
long nStartPos; //File Snippet Start Position U88gJ[$
long nEndPos; //File Snippet End Position 6 l7iX]
int nThreadID; //Thread's ID ]\ t20R{z
boolean bDownOver = false; //Downing is over g9@H4y6fe=
boolean bStop = false; //Stop identical pch8A0JAl)
FileAccessI fileAccessI = null; //File Access interface <kKuis6h
pMd!Jl#(N
X"g`hT"i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r7-H`%.
{ }h1y^fuGi
this.sURL = sURL; uSUog+i
this.nStartPos = nStart; C2H2*"
this.nEndPos = nEnd; bMB*9<c~
nThreadID = id; <RuLIu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %>Mcme>(W
} >f70-D28
jM:|%o
L [&|<<c
public void run() `Gh J)WA<
{ pU1miA '
while(nStartPos < nEndPos && !bStop) I(>j"H)cAF
{ m ;yIFO
fLZ mQO
u4h.\ul8%
try{ 7ygz52
URL url = new URL(sURL); 4Q:r83#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sGG q~7
httpConnection.setRequestProperty("User-Agent","NetFox"); ^Q9K]Vo
String sProperty = "bytes="+nStartPos+"-"; KzQuLD(e
httpConnection.setRequestProperty("RANGE",sProperty); rlY n"3%
Utility.log(sProperty); kQD~v+u{`
TeKU/&fkc
B*:W`}G]_c
InputStream input = httpConnection.getInputStream(); ?-JW2 E"uT
//logResponseHead(httpConnection); m=rMx]k
q\xsXM
v^aI+p6
byte[] b = new byte[1024]; zMh`Uqid
int nRead; Rk#p zD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jHk.]4&0
{ sKC(xO@L;`
nStartPos += fileAccessI.write(b,0,nRead); E]W :
//if(nThreadID == 1) ~d-Q3n?zR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %xA-j]%?ep
} %k @4}M>
RQU-]qQ8BM
!uP8powO
Utility.log("Thread " + nThreadID + " is over!"); 8>`8p0I$+
bDownOver = true; Oj '^Ww m
//nPos = fileAccessI.write (b,0,nRead); b%7zu}F
} b9VI(s>
catch(Exception e){e.printStackTrace ();} }Z)YK}_1
} Q w)U
} w5=<}1`St
Zn:]?%afdO
e5(c,,/
//打印回应的头信息 .|0$?w
public void logResponseHead(HttpURLConnection con) ^%O$7*
{ <Ok7-:OxA
for(int i=1;;i++) }U?:al/m
{ o1thGttVDg
String header=con.getHeaderFieldKey(i); *onVG5<
if(header!=null) ; W$.>*O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .E;}.X
Utility.log(header+" : "+con.getHeaderField(header)); Ld 0j!II(
else `4wy *!]
break; -Gjz+cRns
} 4kR;K!@k
} Q)\[wYMt
2V*;=cv~z
MAQ-'s@
public void splitterStop() Y$_^f*sFn
{ -.K'rW
bStop = true; 6=96^o*
} !-t"}^)
WW-}c;cnK
? M.'YB2
} XB a^ A
*ZIX76y<!A
iD/+#UTY
/* S<z8
**FileAccess.java N{<5)L~Y
*//文件访问(定位，写) !Wj`U$];
package NetFox; 3xgU=@!;
import java.io.*; =&PO_t5)z
hqV_MeHv'
%Vfr#j$=
public class FileAccessI implements Serializable{ 58R.`5B
m~4ik1wq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8( Q[A
RandomAccessFile oSavedFile; 5 BeU/
long nPos; u Yc}eMb
O&sUPv
^!$=(jh.
public FileAccessI() throws IOException k"E|E";B
{ yv: Op\;R
this("",0); &3SmTg %
} H9Vn(A8&`
`JyI`@,!
>1HXC2 Y
public FileAccessI(String sName,long nPos) throws IOException }"[/BT5t
{ I8|"h8\
oSavedFile = new RandomAccessFile(sName,"rw"); > w SI0N
this.nPos = nPos; MRT<hB
oSavedFile.seek(nPos); ]Bs{9=2
} k%iwt]i%
"whs?^/
fcy4?SQ.<i
public synchronized int write(byte[] b,int nStart,int nLen) /N,\st
{ ,eSpt#M
int n = -1; 7jGfQ
try{ 0}po74x*r
oSavedFile.write(b,nStart,nLen); CZ>Ujw=&k
n = nLen; qRz /$|.
} ( X+2vN
catch(IOException e) S;oRE'kk
{ ^1<i7u
e.printStackTrace (); &Lbwx&!0b
} ?!.J0q
S+*>""=
,$U~<Zd
return n; !pHI`FeAV
} "sWsK %
x$FcF8
<9c{Kt.5(
} OLV3.~T
>CwI(vXn
Eo6qC?5<
/* $LcMG,8%_
**SiteInfoBean.java }}bMq.Q'
*/ =J]M#6N0
package NetFox; 9W-1P}e,
8"p rWAN
|:,`dQfw
public class SiteInfoBean { 1H-~+lf
N#@v`S
'8FHn~F
private String sSiteURL; //Site's URL .v-2A);I
private String sFilePath; //Saved File's Path r]]:/pw?t
private String sFileName; //Saved File's Name BK wo2=m~
private int nSplitter; //Count of Splited Downloading File s'OK])>`
EVE"F'Ww,_
&.PAIe.
public SiteInfoBean() e_g&L)
{//nSplitter的缺省值为5 ux,eY
//default value of nSplitter is 5 SLp nVD:'1
this("","","",5); D(WV k
} p*Yx1er1
7]~|dc(
<9T,J"y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b `bg`}x
{ +;=>&XR0m
sSiteURL= sURL; /c6]DQ<?
sFilePath = sPath; o)$eIu}Wg
sFileName = sName; LI^D\
this.nSplitter = nSpiltter; -BWWaL
cl |}0Q5
IRTWmT jT
} S~&9DQNj
8iM:ok
=kCiJ8q|
public String getSSiteURL() }^P"R[+4u
{ `cIeqp
return sSiteURL; E,cQ9}/
} yU"#2 *C
P% 8U
P>$+XrTE
public void setSSiteURL(String value) Om_ "X6
{ hh2&FI
sSiteURL = value; ]z| 2
} [nlq(DGJhp
K<%8.mZ7
p["pGsf
public String getSFilePath() fI'+4 )@x
{ a^ys7UV
return sFilePath; l.Z+.<@
} nZG zez
k_?~@G[I
`tcX[(`
public void setSFilePath(String value) ^NM>xIenf
{ F+j"bhe
sFilePath = value; B~J63Os/
} @;KvUR/+FE
JbMp /
8Qj1%Ri:U
public String getSFileName() 9[DlJ@T}
{ J3B+WD]
return sFileName; Z&=Oe^
} }mI0D>n
;7QG]JX
rFUd
public void setSFileName(String value) :LC3>x`:
{ IWI$@dng6
sFileName = value; x?od_M;*8;
} wF59g38[z$
" RIt
!lA~;F
public int getNSplitter() *y$CDv
{ kV8qpw}K
return nSplitter; _lRIS_^;eE
} hzpl;Mj
~-uDN)
'(ZT}N
public void setNSplitter(int nCount) OYb:);o,iE
{ |`fuu2W!
nSplitter = nCount; c0w1 N]+Ne
} 4vkqe6
} ?sR(
"9N;&^I
!1A< jL
/* L"0?g(< 5
**Utility.java fN:FD`
*/ S@y?E}
package NetFox; {A5$8)nl|
;lt8~ea
uD[T l
public class Utility { 09{s'
U!E}(9 tb
563ExibH
public Utility() N^k& 8
{ 7{9M ^.}
v yt|x5
<'BsQHI
} .CNwuN\
aSgKh
//线程睡眠 rEbH<|
public static void sleep(int nSecond) .'h^
{ oiD{Z
try{ ml!c0<
Thread.sleep(nSecond); G|||.B8
} (uC@cVkP
catch(Exception e) 'Z%1Ly^b
{ ->7zVAX
e.printStackTrace (); 0F%?<: &
} yL -}E
} I7#JT?\}
d<WNN1f
//日志 Vl>KeZ+
public static void log(String sMsg) oMOh4NH,x
{ yJ6g{#X4K<
System.err.println(sMsg); ;vbMC74J#
} {>XoE %
6Ypc]ym=J
] ;CJ6gM~
public static void log(int sMsg) a`?Vc}&
{ 5PC:4
System.err.println(sMsg); {wDe#c{_
} <Of-,PcCV
} v!$?;"d+
`O;4b#!g
@Pi]kWW})
/* 2^w{Hcf
**TestMethod.java .[3C
*/ Z%=A[`5]
package NetFox; 5w+&plIJ
c~OvoTF,
@D `j
public class TestMethod { PSX o"
nV`W0r(f'
y9=<q%Kc-
public TestMethod() K8_\U0 K
{ ///xx/weblogic60b2_win.exe e~cg (.
try{ |x>5T}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,|,kU0xXz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Cb.M
SiteFileFetch fileFetch = new SiteFileFetch(bean); */K]sQZa
fileFetch.start(); og&h$<uOZt
} B7'yc`)H
catch(Exception e){e.printStackTrace ();} Q&"oh
y0/FyQs
` K0PLxSv
} ]&`=p{Z
S1m5z,G
#EB Rc4>,
public static void main(String[] args) .b^!f<j
{ >.G#\w
new TestMethod(); Kc#1H|'2N
} `R-?+76?
} U3UA
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