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)); ( gO?-0
} _~_04p
for(int i=0;i<nEndPos.length-1;i++) NKLGbH
{ SqFya
nEndPos = nStartPos[i+1]; ];6c/#2x
} rwFR5
nEndPos[nEndPos.length-1] = nFileLength; wRb%-s
} 7CUu:6%
} _)2.#L
zc]F
j>eL&.d
//启动子线程 _`/0/69
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wQ!~c2a<8
for(int i=0;i<nStartPos.length;i++) p+;Re2Uyg
{ |K'{R'A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %cO;{og M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m(nlu
nStartPos,nEndPos,i); x@2rfs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?1r@r
fileSplitterFetch.start(); 7GfgW02
} wxsJB2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), twt Bt L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lf0/0KH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Vv' e,m
nEndPos = " + nFileLength); MTb}um.($
// fileSplitterFetch[nPos.length-1].start(); PTA;a0A
n)} J<
8Nxf2i5
//等待子线程结束 q?8MKf[N
//int count = 0; V|}9d:&O
//是否结束while循环 /`hr)
boolean breakWhile = false; p]`pUw{
84b;G4K
3{Ze>yFE
while(!bStop) ,.]e~O4R
{ C-qsyJgZy
write_nPos(); !W^2?pqN
Utility.sleep(500); _4o2AS:j
breakWhile = true; kR^7Z7+#*
Y@KZ:0<
8jqt=}b
for(int i=0;i<nStartPos.length;i++) pW:h\}%`n
{ jCW>=1:JGY
if(!fileSplitterFetch.bDownOver) I.R3?+tZ
{ 10}oaL S
breakWhile = false; =G}_PRn
break; rZu_"bcJ
} x~s>
} H; TmG<S
if(breakWhile) 2-llT
break; Ms1G&NYP
eN/sW!:P|
eno*JK
//count++; {,IWjt &>
//if(count>4) ?MKf=!w
// siteStop(); X$/3
} \q3H#1A
+n,8o:fU:
~Zl`Ap
System.err.println("文件下载结束！"); r4+w?=`
} qqw6p j
catch(Exception e){e.printStackTrace ();} /T#<g:
} x)"=*Jj
6i.'S5.
6$ IXER
//获得文件长度 C$*`c6R
public long getFileSize() [7<X&Q
{ zmr=iK
int nFileLength = -1; wrqdQ}@(
try{ &@dMk4BH<
URL url = new URL(siteInfoBean.getSSiteURL()); ~pzaX8!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YL){o$-N"J
httpConnection.setRequestProperty("User-Agent","NetFox"); FVY,CeA.
WcH^bAY6
H7Y}qP5X
int responseCode=httpConnection.getResponseCode(); C| Mh<,~E
if(responseCode>=400) 6sP;O,UX
{ ~|DF-t V
processErrorCode(responseCode); JTx}{kVO
return -2; //-2 represent access is error fEVuH]
} 0p2 0Rt
QMtt:f]?i
yqejd_cd
String sHeader; 'Dat.@j
=7e8N&-nv
^]U2Jd
for(int i=1;;i++) H5&>Eny
{ "3\RJ?eW:S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /2FX"I[0V%
//Utility.log(in.readLine()); am%qlN<
sHeader=httpConnection.getHeaderFieldKey(i); 44%H? ,d
if(sHeader!=null) 1/cb;:h>
{ @lTUag'U0
if(sHeader.equals("Content-Length")) 1'aS2vB9
{ xR_]^Get
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .z[+sy_
break; T{)!>)
} +B8Ut{l
} e\yj>tQJg
else UD9h5PgT
break; s|,]Nb=z/
} ZM|>Va/X
} ]ei]) JI
catch(IOException e){e.printStackTrace ();} G x,D'H'
catch(Exception e){e.printStackTrace ();} cU{LyZp
+Og O<P
20fCWVw}?}
Utility.log(nFileLength); {;p/V\
8ZIv:nO$
(XW#,=rYk
return nFileLength; Ys<wWfW
} QlXy9-oJ"
I[4E?
(vI7qD_
//保存下载信息（文件指针位置） I* bjE'
private void write_nPos() wR;l"*j
{ N$y4>g
try{ EXBfzK)a
output = new DataOutputStream(new FileOutputStream(tmpFile)); vaQ,l6z .h
output.writeInt(nStartPos.length); wZC'BLD
for(int i=0;i<nStartPos.length;i++) ~f@<]
{ BMdr.0
// output.writeLong(nPos); AoR`/tr,
output.writeLong(fileSplitterFetch.nStartPos); &a|oJ'clz
output.writeLong(fileSplitterFetch.nEndPos); TM"-X\e~{
} ^-ACtA)
output.close(); iF%q6R
} [=9R5.)c
catch(IOException e){e.printStackTrace ();} .Z^g 7 *s
catch(Exception e){e.printStackTrace ();} B}MJ?uvA
} %]R#}amW
`Ch6"=t
H!Od.$ZIX
//读取保存的下载信息（文件指针位置） 8odVdivh
private void read_nPos() xO.7cSqgw
{ $(NfHIX
try{ ~Fx[YPO,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q6ikJ8E8b
int nCount = input.readInt(); ;T_9;RU<'b
nStartPos = new long[nCount]; Kz<xuulr
nEndPos = new long[nCount]; )F~_KD)7jJ
for(int i=0;i<nStartPos.length;i++) [%@zH
{ RhJ<<T.2
nStartPos = input.readLong(); D3K`b4YV
nEndPos = input.readLong(); 6 %=BYDF
} JxvwquI
input.close(); =3T?U_u@
} 1y@-
catch(IOException e){e.printStackTrace ();} H,I}R
catch(Exception e){e.printStackTrace ();} :D,YR(])
} ew"Fr1UGYZ
7&QVw(:)M
oby*.61?5l
private void processErrorCode(int nErrorCode) ;?[~]"
{ E??%)q
System.err.println("Error Code : " + nErrorCode); C=]3NB>Jc
} =;`YtOL
#<~f~{x
J{Ay(
//停止文件下载 Cn55%:
public void siteStop() [x)e6p)
{ yjr@v!o
bStop = true; l6WcnJ
for(int i=0;i<nStartPos.length;i++) G!~BA*
fileSplitterFetch.splitterStop(); BmM,vllO
7^iAc6QSy3
xL BG}C
} q)~qd$yMS
} 6+FON$8
//负责部分文件的抓取 #.><A8J
**FileSplitterFetch.java 9?:S:Sq
*/ nx4aGS"F:
package NetFox; \fhT#/0N
,YY#ed&l
'-vyQ^
import java.io.*; Z~uKT n
import java.net.*; br;G5^j3?
]M2<I#hF.
./ :86@O
public class FileSplitterFetch extends Thread { KRtu@;?
i#lo?\PO>
ypd?mw&1}
String sURL; //File URL X2`>@GR/>
long nStartPos; //File Snippet Start Position g@2.A;N0
long nEndPos; //File Snippet End Position Z]Y4NO;
int nThreadID; //Thread's ID `#f=&S?k
boolean bDownOver = false; //Downing is over caP
boolean bStop = false; //Stop identical |z'?3?,~
FileAccessI fileAccessI = null; //File Access interface .#@Dn(
m\f_u*
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nADd,|xD3
{ Wa(S20yF
this.sURL = sURL; /RM-+D:Y
this.nStartPos = nStart; =#tQIhX`
this.nEndPos = nEnd; DSC4
nThreadID = id; ]Yg EnZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5avO48;Vc
} u\xm8}A
`$H
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public void run() qJA.+q.e$e
{ HWhKX:`l
while(nStartPos < nEndPos && !bStop) a,~P_B|@
{ m'tk#C
50&F#v%YB
+][P*/Ek
try{ $at|1+bQ
URL url = new URL(sURL); udFju&!W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YZl%JX
httpConnection.setRequestProperty("User-Agent","NetFox"); %?hLo8
String sProperty = "bytes="+nStartPos+"-"; 6W=:`14
httpConnection.setRequestProperty("RANGE",sProperty); Bs?F*,zDJ
Utility.log(sProperty); E<uOk
QZr<=}
9C;Y5E~'L
InputStream input = httpConnection.getInputStream(); uw=Ube(
//logResponseHead(httpConnection); ?vFh)U
k_>{"Rc
C8:"+;
byte[] b = new byte[1024]; }qhK.e
int nRead; 5$U>M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kW&Z%k
{ qD*\}b]9I
nStartPos += fileAccessI.write(b,0,nRead); LFyceFbm
//if(nThreadID == 1) l7,qWSsnK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Zk UuniO
} uR@`T18
Qiw4'xQm
t5X lR]` w
Utility.log("Thread " + nThreadID + " is over!"); #@^w>D6W
bDownOver = true; gF6j6
//nPos = fileAccessI.write (b,0,nRead); j7#GqVS'
} i@5%d!J
catch(Exception e){e.printStackTrace ();} c)MR+'d\WO
} ]Cn*C{
} [IFRwQ^%_O
X'7S|J6s
jHH
//打印回应的头信息 O/9%"m:i
public void logResponseHead(HttpURLConnection con) WV1 Z
{ |HGb.^f?
for(int i=1;;i++) Us,[xQ
{ JjLyV`DJ
String header=con.getHeaderFieldKey(i); _F@p53WE
if(header!=null) "jO3Y/>S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @O}j:b
Utility.log(header+" : "+con.getHeaderField(header)); sLdUrD%
else o?K|[gNi
break; 6bKO;^0
} DhNo +"!z
} otf%kG w
ll\^9 4]Q
k(z<Bm
public void splitterStop() xg,]M/J
{ NK9WrUj)
bStop = true; eD{ @0&
} 8='21@wrN
<nTmZ-;
ef}E.Bl
} <hZ}34?]i2
hYc{9$
lzs(i2pA
/* *rcuhw"^b#
**FileAccess.java D4Y!,7WEVt
*//文件访问(定位，写) CKt|c!3 7
package NetFox; ESxC{ "
import java.io.*; /~l/_Jct@G
}&T<wm!
>'-w%H/
public class FileAccessI implements Serializable{ t9n
j22#Bw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OZ!$%.?l
RandomAccessFile oSavedFile; L\Fu']l
long nPos; >9<8G]vcH
O%K?l}e
S2ppKlVv
public FileAccessI() throws IOException =HV-8C]
{ xcZ%,7
this("",0); HS6Imi
} TdP{{&'9
~26s7S}
#EmffVtY
public FileAccessI(String sName,long nPos) throws IOException frmqBCVJ:
{ {8#N7(%z
oSavedFile = new RandomAccessFile(sName,"rw"); `+hy#1]
this.nPos = nPos; Md>f
oSavedFile.seek(nPos); ok3
} a|P~LMPM
B2G5hbaA
Z0"&
public synchronized int write(byte[] b,int nStart,int nLen) Naf`hE9
{ !*?(Q6
int n = -1; O:,2OMB}B`
try{ P10p<@?
oSavedFile.write(b,nStart,nLen); Ukx/jNyYv
n = nLen; tC?Aso
} 1(?CNW[
catch(IOException e) }^pQbFku
{ n-y^7'v
e.printStackTrace (); iijd$Tv
} -?aw^du
yF/< :
-.b Io
return n; HTUYvU*-
} W7*_T]
^3WIl]
53`9^|:
} 9uw,-0*5
hnsa)@
@0vC v
/* Tw`c6^%^y
**SiteInfoBean.java iM/*&O}
*/ tB,.
package NetFox; g]Xzio&w
68p\WheCal
Qh|-a@
public class SiteInfoBean { u+z .J4w
Ufaqhh
1o|0x\q
private String sSiteURL; //Site's URL 6VH90KAT
private String sFilePath; //Saved File's Path v?YdLR
private String sFileName; //Saved File's Name e7XsyL'|p
private int nSplitter; //Count of Splited Downloading File eg$5z Z
{{.sEi*
Y( 1L>4
public SiteInfoBean() z;bH<cQ
{//nSplitter的缺省值为5 ~'^!udF-
//default value of nSplitter is 5 :7$\X[
this("","","",5); ^_*jp[!`b$
} SRt$4EL21
ZL-uwI!`D
vh|Tb5W<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5W[3_P+
{ IqhICC1V-
sSiteURL= sURL; 7>PF~=
sFilePath = sPath; CJMaltPp&
sFileName = sName; P"R97#C
this.nSplitter = nSpiltter; _.d}lK3$2
\3H<z@;
(30<oE{
} t$]&,ucW#
'a;ini
di3 B=A>3
public String getSSiteURL() ;[TljcbS
{ 943I:, B
return sSiteURL; L4YVH2`0)
} ="3a%\
(orrX Ez
|5oKq'(b
public void setSSiteURL(String value) {yvb$ND|j{
{ Y!++CMzU
sSiteURL = value; Y<p zy8z
} 1DEO3p
<a8#0ojm
WF ?/GN
public String getSFilePath() T!u'V'Ei2
{ qDby!^ryc
return sFilePath; a. h?4+^bN
} xa87xX=a
o &BPG@n
G$;>ueM
public void setSFilePath(String value) v}7@CP]nV
{ Cz'xGW{
sFilePath = value; !lR0w|
} KWFyw>*)
ftYR,!&
b@=zrhQ
public String getSFileName() cT/3yf
{ ;Y Dv.I
return sFileName; P['X<Xt8
} IXGW2z;
[ 3$.*
tO?21?AD D
public void setSFileName(String value) 7*zB*"B'1t
{ qTyg~]e9(
sFileName = value; KK:N [x
} kx|me~I
7d3'CQQ4
'"oo;`g7
public int getNSplitter() >?S\~Y
{ [X;>*-
return nSplitter; %z(9lAe
} WwW"fkv
NNwc!x)*
(N,nux(0k
public void setNSplitter(int nCount) |WB"=PE
{ WI,40&<
nSplitter = nCount; 0(wf{5
} uVN.=
} >HE,'
4Z*|Dsw
,+~2&>wj
/* @Ppo &>
**Utility.java N g58/}zO
*/ y&7YJx
package NetFox; |kId8WtA
q#;BhPc
?#?e(mpo
public class Utility { D^|jZOJ
Uf# PoQ!y
'KSa8;:=C
public Utility() .FuA;:@%\
{ a lrt*V|=
CNut{4
Was'A+GZ
} F#6cF=};@
DYX-5~;!
//线程睡眠 /E)9v$!
public static void sleep(int nSecond) iDZrK%fl
{ <lFdexH"T
try{ ]x2Jpk99a
Thread.sleep(nSecond); ~NxEc8Y
} l$M$o(
catch(Exception e) Hfke
{ 3Q",9(D
e.printStackTrace (); h9)RJSF4
} F@9Y\. ,
} pqJ)G;%9
5)mVy?Z
//日志 `"B^{o
public static void log(String sMsg) Y=9j2 ]t
{ 4KE)g
System.err.println(sMsg); UIn^_}jF`
} ?gLAWz
/M:H9Z8!
V7P6zAJy
public static void log(int sMsg) oB4#J*
{ .vK.XFZ8R
System.err.println(sMsg); qh$X^%g
} c)03Ms4 D
} _D-5}a"
3g;T?E
YX_vv!-]
/* A]j}'
**TestMethod.java zHV|-R
*/ L%f;J/
package NetFox; 57U%`
IdF$Ml#[h
4Hk6b09
public class TestMethod { r ^MiRa
mk\i}U>`
y<|)'(
public TestMethod() h`lmC]X_
{ ///xx/weblogic60b2_win.exe lcCJ?!lsSW
try{ 6%%PP8.F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2% %|fU9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l]$40 j
SiteFileFetch fileFetch = new SiteFileFetch(bean); }%+qP+O\
fileFetch.start(); Y[?`\c|
} LP,9<&"<
catch(Exception e){e.printStackTrace ();} )=Zsv40O
o_O+u%y
EX4 C.C|d
} l&3ki!
PRwu
Q3,=~}ZNK
public static void main(String[] args) *="m3:c'J
{ ?ql2wWsQO
new TestMethod(); l DnMjK\M
} Z:|9N/>T
} VJg,~lQN#t
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