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)); a%| I'r
} FvYgpbEZ
for(int i=0;i<nEndPos.length-1;i++) ~tK4C|
{ Hdvtgss!
nEndPos = nStartPos[i+1]; HYcLXhvgu
} o>WB,i^G
nEndPos[nEndPos.length-1] = nFileLength; <Qg).n>;z
} 8(-V pU
} ffoL]u\
<A|X4;
3y^PKIIrt
//启动子线程 %Ms"LoK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X$*MxMNs
for(int i=0;i<nStartPos.length;i++) Pq\ `0/4_
{ kY>jp@wV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mzw`{Oy>L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e&~vO| 3w%
nStartPos,nEndPos,i); ]oT8H?%*Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dzd[<Qln
fileSplitterFetch.start(); n/W@H Im#
} [|iWLPO1&k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -R%T Dx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J)7\k$D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p7{2/mj
nEndPos = " + nFileLength); pK`1pfih
// fileSplitterFetch[nPos.length-1].start(); WX"iDz.
r<'ni
G47(LE"2b
//等待子线程结束 !8g419Yg
//int count = 0; hcn$uyP
//是否结束while循环 ?^Gi;d5
boolean breakWhile = false; ,+w9_Gy2H
-e_91WI
*Bfo"["0.
while(!bStop) cp1-eR_&
{ /80H.|8O
write_nPos(); ]MD,{T9l\>
Utility.sleep(500); zM+4<k_dH]
breakWhile = true; LZ#=Ks
pbCj ^
{6 #Qm7s-
for(int i=0;i<nStartPos.length;i++) -VZn`6%s
{ jY;T:C-T
if(!fileSplitterFetch.bDownOver) Wd`*<+t]
{ cNbH:r"Ay
breakWhile = false; oW}nr<G{<
break; } 6 ,m2u
} n[S-bzU^t
} \;XDPC j
if(breakWhile) VSx9aVPkC
break; Q};n%&n&
fe!eZiE
'/OcJVSR
//count++; @h&:xA56
//if(count>4) epicY
// siteStop(); }b5omHUE%
} y^!>'cdV
YD3jP}Ym
QhhL_vP
System.err.println("文件下载结束！"); GB%kxtGD;\
} ,NO2{Ha$
catch(Exception e){e.printStackTrace ();} n;@.eC,T/
} Hs:0j$
mXYG^}
!hs33@*u~
//获得文件长度 2jf73$F
public long getFileSize() L<XAvg
{ p< Y-b,&
int nFileLength = -1; o3"Nxq"U
try{ (]E0fjk
URL url = new URL(siteInfoBean.getSSiteURL()); #fYRsVQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K`=9"v'f+
httpConnection.setRequestProperty("User-Agent","NetFox"); HVJqDF
&\>=4)HB;
{MRXKnm;e
int responseCode=httpConnection.getResponseCode(); zRU9Q2Y
if(responseCode>=400) d*YVk{s7V
{ {+~ JTrp
processErrorCode(responseCode); '[Sm w'n6-
return -2; //-2 represent access is error |}7!'f\M
} ]'NL-8x">
nt&"? /s
57fl<IM
String sHeader; 4wMZNa<Sx
y Nc@K|
?gsPHPUS
for(int i=1;;i++) j.&Y'C7GOC
{ KuRJo]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /78zs-
//Utility.log(in.readLine()); ;J@U){R
sHeader=httpConnection.getHeaderFieldKey(i); XS}-@5TI
if(sHeader!=null) 216`rQ}z
{ )x,/+R]{8l
if(sHeader.equals("Content-Length")) 2tb+3K1
{ {RGQX"k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7lx" X0w*m
break; {Gr"lOi*@
} hgj ]Jr
} 0 <E2^
else eB&.keO
break; qfkdQ/fP
} y7t'I.E[+
} 2 \<u;9
catch(IOException e){e.printStackTrace ();} BM~6P|&qD
catch(Exception e){e.printStackTrace ();} *@{
?8do4gT+1
ECyG$j0
Utility.log(nFileLength); _l"=#i@L
rB|1<jR
pO/vD~C>
return nFileLength; ~<.{z]*O
} /-knqv
k|czQ"vaI
y|0!sNg
//保存下载信息（文件指针位置） <vE|QxpR
private void write_nPos() yH(3 m#
{ q@G}Hjn
try{ xHCdtloi?I
output = new DataOutputStream(new FileOutputStream(tmpFile)); B"sB0NuT/$
output.writeInt(nStartPos.length); AdpJ4}|0
for(int i=0;i<nStartPos.length;i++) gg/ts]$
{ YQ@2p?4m
// output.writeLong(nPos); p"FWAC!
output.writeLong(fileSplitterFetch.nStartPos); EKD#s,(V*X
output.writeLong(fileSplitterFetch.nEndPos); v, CWE
} xk
output.close(); `W>Sss
} TCFr-*x
catch(IOException e){e.printStackTrace ();} ;PB_@Zg
catch(Exception e){e.printStackTrace ();} +1a3^A\
} P5H_iH
]h#QA;
m^\&v0
//读取保存的下载信息（文件指针位置） <-mhz`^
private void read_nPos() Y_}_)nE@m
{ G!`PP
try{ 9[`c"Pd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Lu~E5 ,
int nCount = input.readInt(); d-C%R9
nStartPos = new long[nCount]; ;[79Ewd#$
nEndPos = new long[nCount]; joDqv,iW8
for(int i=0;i<nStartPos.length;i++) `M*jrkM]x
{ gKY6S?
nStartPos = input.readLong(); yM}3u4FG
nEndPos = input.readLong(); KYZ#.f@
} ]61Si~Z
input.close(); _R(9O?;q
} Yi]`"\
catch(IOException e){e.printStackTrace ();} 5A$,'%d
catch(Exception e){e.printStackTrace ();} j7^A%9
} t-5K dLB
H|0-Al.{
eIEL';N6
private void processErrorCode(int nErrorCode) W':b6}?
{ @U4hq7xzV2
System.err.println("Error Code : " + nErrorCode); l[]cUE
} )"?eug}D
d&+0JI<
?K;l 5$?%
//停止文件下载 jU kxA7 }}
public void siteStop() Yg?BcY\
{ tUuARo7#
bStop = true; Y]*&\Ex"\
for(int i=0;i<nStartPos.length;i++) j/_&]6!
fileSplitterFetch.splitterStop(); \4LTViY]
Fg 8lX9L
(c&%1bJ
} IBvn q8\
} S8B?uU
//负责部分文件的抓取 ?E_;[(Mcr
**FileSplitterFetch.java nbB*d@"
*/ "G-h8IN^O
package NetFox; kxN O9w
7AS_Aw1L
98)C 7N'
import java.io.*; MRw4?HqB
import java.net.*; B;F~6i
:h |]j[2p
|V4<eF-0S
public class FileSplitterFetch extends Thread { w[D]\>QHa
p!~1~q6
ZDAW>H<
String sURL; //File URL ).IyjHY
long nStartPos; //File Snippet Start Position ~#4FL<W
long nEndPos; //File Snippet End Position 8MI8~
int nThreadID; //Thread's ID Mo<q(_ZeRP
boolean bDownOver = false; //Downing is over c_CVZR?
boolean bStop = false; //Stop identical g~b$WV%
FileAccessI fileAccessI = null; //File Access interface Bu&9J(J1
$=Ns7Sbup
@tPr\F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c{dabzLy
{ ;BqCjS%`N
this.sURL = sURL; n((A:b
this.nStartPos = nStart; zfE8=d8U
this.nEndPos = nEnd; >MKj~Ud
nThreadID = id; k0O5c[j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %LzARTX
} P[-do
*Ti"8^`6
]j>`BK>FE
public void run() XXhN;-p
{ n-xdyJD
while(nStartPos < nEndPos && !bStop) _'ebXrbZB
{ #AB5}rPEI
'e' p`*
7i{(,:
try{ *Ow2,{Nn
URL url = new URL(sURL); W;cYg.W2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tk*-Cx?_
httpConnection.setRequestProperty("User-Agent","NetFox"); +t%2V?
String sProperty = "bytes="+nStartPos+"-"; ;9WUt,R
httpConnection.setRequestProperty("RANGE",sProperty); W7b m}JHn
Utility.log(sProperty); $2}#):`
JB].ht
:\qapFV
InputStream input = httpConnection.getInputStream(); \o/eF&
//logResponseHead(httpConnection); M2w'cdHk
9&uf
09anQHa
byte[] b = new byte[1024]; \>pm (gF
int nRead; QK#wsw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nw%9Qw
{ p/RT*?<
nStartPos += fileAccessI.write(b,0,nRead); OA=~i/n~
//if(nThreadID == 1) (xN1?qXB.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2_)UHTwsK
} 9M3"'^ {$
DpvHIE:W
d"miPR
Utility.log("Thread " + nThreadID + " is over!"); z'$1$~I
bDownOver = true; rD4umWi
//nPos = fileAccessI.write (b,0,nRead); "f_qG2A{
} K)wWqC.
catch(Exception e){e.printStackTrace ();} TEY~E*=}$
} X?[ )e
} CYQ)'v
G%: 3.:E"
kyvl>I0q@
//打印回应的头信息 GVJ||0D
public void logResponseHead(HttpURLConnection con) ]uypi#[
{ (DY[OIHI
for(int i=1;;i++) Xpn\TD<_I
{ [2Zy~`*y{
String header=con.getHeaderFieldKey(i); 0QW=2rs
if(header!=null) wiZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S} OO)
Utility.log(header+" : "+con.getHeaderField(header)); 2vLun
else 72"H#dy%U
break; ;h+~xxu=X
} [RN]?,
} 5|*`} ;/y
N'9T*&o+
z8awND
public void splitterStop() ;*<R~HJt
{ C$PS@4'U
bStop = true; 'UWkJ2:!
} tkcs6uy
oC49c~`8
jF0"AA
} RPgz"-
J](NCD
S<Gm*$[7
/* CN:T$ f|)
**FileAccess.java ^ex\S8j
*//文件访问(定位，写) Zs=A<[
package NetFox; NT.#U?9c
import java.io.*; &xN+a{&
&`v?oN9$
UAhWJ$(C
public class FileAccessI implements Serializable{ kl.;E{PL
;]Q6K9.d8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'WE"$1
RandomAccessFile oSavedFile; CAC4A
long nPos; 3MNM<Ih
"W%YsN0
A| A#|D
public FileAccessI() throws IOException wV==sV
{ C&H'?0Y@
this("",0); Fy Ih\
} J'|=J
jb&MC2
y< *-&
public FileAccessI(String sName,long nPos) throws IOException A8vd@0
{ FUI*nkZY
oSavedFile = new RandomAccessFile(sName,"rw"); b;UDgq8v
this.nPos = nPos; pN5kcvQ
oSavedFile.seek(nPos); HS{Vohy>
} N=<`|I
|_TI/i>?'
px K&aY8
public synchronized int write(byte[] b,int nStart,int nLen) "nu]3zcd
{ sb{K%xi%
int n = -1; zG6l8%q'UE
try{ !9_(y~g{N
oSavedFile.write(b,nStart,nLen); I@ueeDY
n = nLen; 'Y)aGH(
} yj&GJuNb~
catch(IOException e) cZ:jht
{ XlU\D}zS
e.printStackTrace (); "Esl I
} K$h\<_V
y'!OA+ob
n>q!m@ }<
return n; %T]^,y$n
} K9k!P8Rd
Q*>)W{H&)
x5Lbe5/P
} 37zBX~
:,JaOn'
3Xu|hkK\e
/* ]E<Z5G1HD
**SiteInfoBean.java yqq1a o
*/ O68-G
package NetFox; JpfA+r
>[;@ [4}
5;0w({1l
public class SiteInfoBean { B-C$>H^
`-pwP
baII!ks
private String sSiteURL; //Site's URL hYkkr&
private String sFilePath; //Saved File's Path =Z:]%
private String sFileName; //Saved File's Name Mc@9ivwL#
private int nSplitter; //Count of Splited Downloading File JfN5#+_i
!t23 _b0
,]2?S5R
public SiteInfoBean() bzNnEH`^]
{//nSplitter的缺省值为5 ?`U_|Yo
//default value of nSplitter is 5 xOe1v9<
this("","","",5); UGO;5!
} XMI*obS'z
]LC4rS
hI86WP9*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F0U %m
{ }MRgNr'k
sSiteURL= sURL; >6o <Q
sFilePath = sPath; Qt+D ,X
sFileName = sName; larv6ncV
this.nSplitter = nSpiltter; Dz~0(
-pYmM d,
Ea@0>_U|
} f1_;da
pRobx
L K#A
public String getSSiteURL() o7!A(Eu
{ 8IlUbj
return sSiteURL; $?PI>9g!
} ?l9sj]^w
XZ |L D#
:.+w'SEn4M
public void setSSiteURL(String value) {:gx*4}q8
{ 1YV1Xnn,
sSiteURL = value; 6m;>R%S_
} *m"9F'(Sd
9xK>fM&u
@n)?=[p
public String getSFilePath() / 3N2?zS{
{ {S=<(A@
return sFilePath; uQO5GDuK>
} m0bxVV^DK!
r*`e%`HU
@GKDSS4jv
public void setSFilePath(String value) SiaNL:
{ *B|hRZka1A
sFilePath = value; qB$-H' j:;
} s1 >8uW
|URfw5Hm
%"H:z
public String getSFileName() FFw(`[A_
{ +yO) 3
return sFileName; Wa^Wn +r
} #'&-S@/nQs
-w"I
o!BCR:
public void setSFileName(String value) &s`)_P[
{ bPFGQlmIO
sFileName = value; B9"o Ru^}
} HKJCiQ|k
5_!L"sJ
\7LL neq
public int getNSplitter() jv~#'=T'
{ F`:Q
return nSplitter; bra2xHK@
} ,h^6y
:(~<BiqR(
nN{DO:_o
public void setNSplitter(int nCount) RkG?R3e
{ P}Ig6^[m\
nSplitter = nCount; w]gLd
} E^rBs2;9
} bKS/T^UQ
EcHZmf
I'P|:XKI
/* _K9PA[m5~
**Utility.java 3J"`mQ
*/ uN<=v&]q
package NetFox; (>0`e8v!
KcV"<9rE
z#Jw?K_
public class Utility { l5w^rj
k$%{w\?Jf
#eKKH]J/
public Utility() a^&"gGg
{ }` 3-
\5}PF+)|
;b [>{Q;
} =r/K#hOR\J
6E) T;R(@
//线程睡眠 co\?SgE35
public static void sleep(int nSecond) TYuP EVEXZ
{ ph6/+[:
try{ |gA@$1+}
Thread.sleep(nSecond); 9q?knMt
} 5]*lH t
catch(Exception e) bq7+l4CGTv
{ ]xvhUv!G
e.printStackTrace (); YTTy6*\,_
} E4Q`)6]0
} uO1^Q;F
Tr;.%/4Q
//日志 "-S!^h/v
public static void log(String sMsg) h:Gs9]Lvtv
{ =&pR=vl
System.err.println(sMsg); DH\Ox>b=
} 9'p| [?]v
aN"YEL>w
LeN }Q
public static void log(int sMsg) TgV-U
{ ?5">50
System.err.println(sMsg); \_.'/<aQ
} mL1ZSX o!
} 1R-0b{w[
6'*6tS
[5xm>Y&}
/* gs1
**TestMethod.java |6-9vU!LK?
*/ }%w;@[@L
package NetFox; K_U`T;Z\
.nIGs'P
$]?pAqU\
public class TestMethod { 27gHgz}}
0*:n<T9
tz65Tn_M
public TestMethod() #p=+RTZ<
{ ///xx/weblogic60b2_win.exe %+/v")8+?
try{ 1<x5{/CZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); e#5WX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N/-(~r[
SiteFileFetch fileFetch = new SiteFileFetch(bean); CPa+?__B
fileFetch.start(); gm]q<~eMW
} ?z)2\D
catch(Exception e){e.printStackTrace ();} \Yp"D7:Qi
t#M[w|5?
ShRMzU
} hK4ww"-
=:T"naY(
P `<TO
public static void main(String[] args) ;xTMOuI*
{ ?}^ y6
new TestMethod(); 9i#,V@
} T\zn&6
} ~xam ;]2
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