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)); hc'-Dh
} %Pqf{*d8
for(int i=0;i<nEndPos.length-1;i++) 1M}&ZH
{ :G<E^<M\)^
nEndPos = nStartPos[i+1]; _z1(y}u}
} MC{ 2X
nEndPos[nEndPos.length-1] = nFileLength; 44F`$.v96
} Rh>}rGvCUN
} Ey4z.s'-l
qvv2O1c"A
C|?o*fQ
//启动子线程 {U_$&f9s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R?p00
for(int i=0;i<nStartPos.length;i++) {4-[r#R<M
{ Yp:KI7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ($~RoQ=0S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y)}Rb6qGW
nStartPos,nEndPos,i); QurW/a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZPD[5)~
fileSplitterFetch.start(); Cj?L@%"
} ubmrlH\d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eEn;!RS)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V}zEK0n(6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NMi45y(Y
nEndPos = " + nFileLength); bcZf>:gVf
// fileSplitterFetch[nPos.length-1].start(); jr`Ess
leQT-l2Bk
59Gk3frk(
//等待子线程结束 B.L]Rk\4
//int count = 0; b?j< BvQ
//是否结束while循环 U2%.S&wS,e
boolean breakWhile = false; "5,
dzkw$m^@^
0]jA<vLR
while(!bStop) p}<w#p |
{ ~jb"5CX
write_nPos(); ]J#9\4Sq
Utility.sleep(500); vC5n[0
breakWhile = true; i}~SDY
nYJTKU
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for(int i=0;i<nStartPos.length;i++) @ G4X
{ +Lnsr\BA
if(!fileSplitterFetch.bDownOver) q`G,L(
{ ScSZGs 5&
breakWhile = false; "XT"|KF|D
break; 1\r|g2Z :
} =ID 2
} >X51$wBL
if(breakWhile) >B>CB3U
break; BY]i;GVq
p^pOuy8
=?-ye!w
//count++; IO/4.m-aN#
//if(count>4) 41_SRh7N
// siteStop(); .n=Z:*JqQ
} kVD(Q~<
%G?;!Lz
1DA1N<'
System.err.println("文件下载结束！"); {Ions~cO)
} T_lsGu/
catch(Exception e){e.printStackTrace ();} ymNnkFv
} mB\C?=_
MBXBog7U
~%2pp~1K
//获得文件长度 sIv)'
public long getFileSize() jU5}\oP@
{ 7^Yk`Z?|a
int nFileLength = -1; wm+})SOX9
try{ ,p9i%i
URL url = new URL(siteInfoBean.getSSiteURL()); I=!rbF;Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l]]l
httpConnection.setRequestProperty("User-Agent","NetFox"); +GAf O0
"rAY.E]
3bNIZ#`|MB
int responseCode=httpConnection.getResponseCode(); VG>vn`x>a
if(responseCode>=400) Z,.G%"i3C
{ 5~yNqC
processErrorCode(responseCode); x[Wwq=~
return -2; //-2 represent access is error ^`D=GF^tX
} L.=w?%:H=
g5q$A9.Jl
U-^[lWn[@4
String sHeader; tM#lFmdd\P
@;?T~^nGj
^xZ e2@
for(int i=1;;i++) $v b,P(
{ c c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =-o'gL
//Utility.log(in.readLine()); Ea(,aVlj
sHeader=httpConnection.getHeaderFieldKey(i); &k8vWXMGk%
if(sHeader!=null) w;e(Gb%9
{ A4QcQ"
if(sHeader.equals("Content-Length")) W8g'lqc|
{ h},oF!,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p\Lq}tk<
break; {W\T"7H
} SAY f'[|w
} 4R8G&8b
else _pH{yhA
break; d` Sr4c
} +B|7p9qy
} 28OWNS M=
catch(IOException e){e.printStackTrace ();} :5yV.7
catch(Exception e){e.printStackTrace ();} %AW4.3()8
n$:IVX"2b
"+uNmUUnm
Utility.log(nFileLength); Ap$y%6
> MG>=A
UgN28YrW
return nFileLength; -!({BH-M_
} pDhse2
#pHs@uvO
_U{&@}3
//保存下载信息（文件指针位置） &J!aw
private void write_nPos() 6q>+!kXh
{ [/_+>M
try{ =\t /u
output = new DataOutputStream(new FileOutputStream(tmpFile)); dXn%lJ
output.writeInt(nStartPos.length); 5TUNX^AW
for(int i=0;i<nStartPos.length;i++) s9oO%e<
{ LG]3hz9^9
// output.writeLong(nPos); &5t :H 8b
output.writeLong(fileSplitterFetch.nStartPos); -xD*tf*
output.writeLong(fileSplitterFetch.nEndPos); aV1lJ;0
} Hk7K`9
output.close(); -]:GL>b
} 7'NS9|
catch(IOException e){e.printStackTrace ();} [\Qr. 2
catch(Exception e){e.printStackTrace ();} cubUq5
} \x>65;
O3o: qly!
>ulY7~wUv
//读取保存的下载信息（文件指针位置） *xR 2)u
private void read_nPos() a8AYcEb
{ yA[({2%
try{ x&A vUJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +!0eu>~_&
int nCount = input.readInt(); S|B$c E
nStartPos = new long[nCount]; H@uE>
nEndPos = new long[nCount]; EC6k{y}bA
for(int i=0;i<nStartPos.length;i++) :"o o>
{ 8p1ziz`4>$
nStartPos = input.readLong(); k8]O65t|
nEndPos = input.readLong(); =iHiPvP0
} ug`NmIQP
input.close(); ;PyZ?Z;
} >\A8#@1
catch(IOException e){e.printStackTrace ();} k#:2'!7G
catch(Exception e){e.printStackTrace ();} n+1y
} Qju`e Eo
#hw/^AaD-
b.2J]6G
private void processErrorCode(int nErrorCode) 3_5XHOdE
{ W0cgI9=9
System.err.println("Error Code : " + nErrorCode); %}>dqUyQ
} /Y^8SO4
|vFj*XU
`3q;~ 9
//停止文件下载 DW(~Qdk
public void siteStop() 0F;,O3Q
{ 1f(DU4h
bStop = true; k6\^p;!Y
for(int i=0;i<nStartPos.length;i++) C+NF9N
fileSplitterFetch.splitterStop(); {w^uWR4f
jQj,q{eA
E&~nps8e
} giavJ|
} 7 boJ*
//负责部分文件的抓取 kVDe6},D7
**FileSplitterFetch.java G.U5)4_^
*/ 4-v6=gz.
package NetFox; 5 ZfP
Me:{{-V4
?PPZp6A3L=
import java.io.*; v@EQ^C2.&
import java.net.*; yy(A(}
bb=uF1
F#+.>!
public class FileSplitterFetch extends Thread { Ey&aBYR
HT`1E0G8)
oYM,8 K
String sURL; //File URL >E"9*:.^a
long nStartPos; //File Snippet Start Position u2sR.%2U<
long nEndPos; //File Snippet End Position rU#li0 >
int nThreadID; //Thread's ID mxqG-*ch-
boolean bDownOver = false; //Downing is over ?n'OFpd
boolean bStop = false; //Stop identical %kU'hzLg
FileAccessI fileAccessI = null; //File Access interface q9}m!*8e
eK`PxoTI-I
,|To#umym>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .\5$MIF
{ (%<'A
this.sURL = sURL; ]re'LC!d
this.nStartPos = nStart; %c6E-4b
this.nEndPos = nEnd; "<l<& qp
nThreadID = id; G5'_a$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W."f8ow
} -)w]a{F
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public void run() S]2 {ZDP
{ \3PE+$
while(nStartPos < nEndPos && !bStop) cBEHH4U
{ t;#Gmo
zX5G;,_
fnH3CE
try{ hG Apuy
URL url = new URL(sURL); M$&>5n7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #s+X+fe
httpConnection.setRequestProperty("User-Agent","NetFox"); E8-53"m
String sProperty = "bytes="+nStartPos+"-"; YL5>V$i
httpConnection.setRequestProperty("RANGE",sProperty); y@apJ;_R-
Utility.log(sProperty); v:d9o.h
Q~ 0Dfow?
68x}w Ae
InputStream input = httpConnection.getInputStream(); MTmO>V&O
//logResponseHead(httpConnection); qa!RH]B3
4#Eul
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byte[] b = new byte[1024]; mtw9AoO
int nRead; g"y?nF.&F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BXTN>d27
{ +Z+ExS<#z
nStartPos += fileAccessI.write(b,0,nRead); W(@>?$&
//if(nThreadID == 1) zk>h u<_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SFO&=P:U
} D<nxr~pQ
!A[S6-18%-
2a[9h#
Utility.log("Thread " + nThreadID + " is over!"); AMk~dzNt
bDownOver = true; KU2$5[~j
//nPos = fileAccessI.write (b,0,nRead); fI11dE9&?[
} $!`L"szqD*
catch(Exception e){e.printStackTrace ();} 5G?.T?
} W/v|8-gcK
} YsAF{
k|#Zy,
#?m{YT{P
//打印回应的头信息 -2lRia
public void logResponseHead(HttpURLConnection con) *ro.mQ_
{ 3A R%&:-
for(int i=1;;i++) ){tPP$-i=
{ ]p$zvMf}
String header=con.getHeaderFieldKey(i); \GHOg.P
if(header!=null) ~hD{coVTI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +k rFB?>`
Utility.log(header+" : "+con.getHeaderField(header)); l10-XU02
else *g$agyOfh
break; X')S;KW
} $,P\)</VR
} '49L(>.
/c^e&D
T~:_}J
public void splitterStop() GYqJ!,
{ r{V.jZ%p'Z
bStop = true; h[H%:743
} Ej|A ; &E
m0Z7N5v)
1NGyaI
} ~'[jBn)
RHXvee55
Dqr9Vv
/* M c@GH
**FileAccess.java oeGS
*//文件访问(定位，写) Bbs5f@E
package NetFox; f+^c@0que
import java.io.*; xOM_R2Md
08io<c,L
O0zi@2m?B
public class FileAccessI implements Serializable{ VIYV92[
wWFW,3b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "7?t)FOo
RandomAccessFile oSavedFile; MHNe>C-!q
long nPos; t 2G1[j!
u#VweXyU
Z^+a*^w~{
public FileAccessI() throws IOException D1! {S7
{ 1t%<5O;R
this("",0); wQw-:f-
} `uhL61cMp
.$^wy3:F"
CLktNR(45
public FileAccessI(String sName,long nPos) throws IOException r_=p,#}#
{ )(.%QSA\C
oSavedFile = new RandomAccessFile(sName,"rw"); X}?ESjZJ
this.nPos = nPos; (NM6micc
oSavedFile.seek(nPos); <>&89E%j'
} c&A]pLn+x
z0;9SZ9
4)E|&)-fu8
public synchronized int write(byte[] b,int nStart,int nLen) }8 \|1@09
{ uegb;m
int n = -1; :Lc3a$qtx5
try{ L77EbP`P
oSavedFile.write(b,nStart,nLen); #Wq#beBb
n = nLen; X,&xhSzg?
} {\luieG
catch(IOException e) Y 0]Kl^\A
{ 4UazD_`'
e.printStackTrace (); -g<cinNSp
} tnNZ`]qY
pr)K{~m]{<
#a.\P.{L
return n; Kf&r21h
} S8vx[<
6_Fpca3L
UMv"7~
} j]#wrm
GA7u5D"0
Q{8qm<0g
/* rEg+i@~
**SiteInfoBean.java <gR`)YF7
*/ 8 `o{b"l+
package NetFox; C*$|#.l
s7vPI
]}/mFY?7
public class SiteInfoBean { |o|gP8
yIlV[_
F1E.\l
private String sSiteURL; //Site's URL *|@+rbjVC
private String sFilePath; //Saved File's Path |zT%$
private String sFileName; //Saved File's Name *WD;C0?z
private int nSplitter; //Count of Splited Downloading File ,v|CombIc.
TJE% U0Ln
N*HH,m&
public SiteInfoBean() u1wg C#
{//nSplitter的缺省值为5 4VC/-.At
//default value of nSplitter is 5 9armirfV'P
this("","","",5); ;Sy/N||
} z( *]'Y
l#p}{
KQ-,W8Q5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a (P^e)<
{ P_v0))n{
sSiteURL= sURL; }FHw" {my
sFilePath = sPath; EqVsxwa
sFileName = sName; C+T&O
this.nSplitter = nSpiltter; qjJ{+Rz2
$+0=GN
`D4oAx d9
} `!]R!T@C
4n#YDZ
G]1(X38[si
public String getSSiteURL() "^Y6ctw
{ }7-7t{G
return sSiteURL; `Fz\wPd
} &3jBE--
;HR 6X
VjC*(6<Gj
public void setSSiteURL(String value) te4F"SEf
{ /A0 [_
sSiteURL = value; U0!^m1U:
} 0`V3s]%iu
LG"c8Vv&)~
sg+ZQDF{x
public String getSFilePath() z|Hy>|+
{ m*\B2\2gJ
return sFilePath; f2`P8$U)R
} qPL^zM+
r9+E'\
H&~5sEGa
public void setSFilePath(String value) 2f`WDL
{ @][ a8:Y9I
sFilePath = value; "xL;(Fqu
} f37ji
e 4 p*51ra
q-A`/9
public String getSFileName() fEx+gQW_
{ <jpeu^7
return sFileName; Rrh<mo(yj#
} x%_qJ]o
oNiToFbQu
:= ]sq}IN
public void setSFileName(String value) JmnBq<&,0
{ R)sp
sFileName = value; 3Ne9%"
} i7i|370
-iY9GN89c
aQ32p4C
public int getNSplitter() -3C* P
{ muL>g_H
return nSplitter; LvSP #$f
} EC^Ev|PB\u
b24NL'jm
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public void setNSplitter(int nCount) b*btkaVue
{ 2N L:\%wz
nSplitter = nCount; >{phyByI
} NvQY7C
} |WD,\=J2
pe\Txg6
l,imT$u
/* #]5&mKi
**Utility.java y%{*uH}SL
*/ S4#A#a2J
package NetFox; y_}K?
cmwzKu%
34X(J-1\|i
public class Utility { f}L>&^I)
u@GRN`yn
nQ:ml
public Utility() *,O :>Z5I
{ NmH}"ndv+
2E@C0HaL
A6@+gP<
} C ffTv
UgF)J
//线程睡眠 gi1}5DR
public static void sleep(int nSecond) o|rGy5
{ n/KI"qa]9
try{ K[iY{
Thread.sleep(nSecond); Y|hzF:ll
} s|{^ }4{
catch(Exception e) I}*]m%'-Y
{ Ma`
e.printStackTrace (); aHBByH
} }V1DyLg:
} >XD02A[
+Z 93`
//日志 [(D}%+2
public static void log(String sMsg) NZfo`iHAN
{ 1Qp1Es<)
System.err.println(sMsg); W+#}~2&Dv
} H]%mP|
?c|`R1D
J]n7| L
public static void log(int sMsg) u\Nw:Uu i
{ "'Q"(S
System.err.println(sMsg); gt2>nTJz.Z
} zPX=MfF
} afxj[;p!
zxk??0]/
%4|n-`:
/* _'?8s6 H
**TestMethod.java RT.wTJS;
*/ WU+Jo@]y
package NetFox; `@u+u0
vSyi}5D
NPB,q& Th
public class TestMethod { 8I5VrT
|1_$! p
9E->;0-
public TestMethod() H3p4,Y}'#
{ ///xx/weblogic60b2_win.exe +P> A P&
try{ X]+(c_i:hC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]X>QLD0W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +(QMy&DtS
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;JPbBwm
fileFetch.start(); Lyf? V(S
} hr~qt~Oi
catch(Exception e){e.printStackTrace ();} !T#8N7J>
/ygUd8@
[T}%q"<
} %#S"~)
D]G'R5H
?c=R"Yg$
public static void main(String[] args) rvwl
{ Ab^>z
new TestMethod(); l ))~&
} %U=S6<lbj;
} ~n8*@9[
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