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)); #6za
} ^vr`t9EE
for(int i=0;i<nEndPos.length-1;i++) -MItZ
{ N}7tjk
nEndPos = nStartPos[i+1]; 22"/|S
} u|8yV.=R
nEndPos[nEndPos.length-1] = nFileLength; S@vLh=65
} BCw0kq@
} <m+$@:cO
5#$5ct
av}pT)]\
//启动子线程 ^?gs<-)B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Cs8e("w
for(int i=0;i<nStartPos.length;i++) ^ ,yh384
{ ;T?4=15c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I~NQt^sg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3&7$N#v
nStartPos,nEndPos,i); nnBl:p>< k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qJLtqv
fileSplitterFetch.start(); pax;#*QcQ
} C]DvoJmBs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TkV*^j5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e"6!0Py#*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \&5t@sC
nEndPos = " + nFileLength); CDgu`jj%]
// fileSplitterFetch[nPos.length-1].start(); x)!NB99(tC
s9b 6l,Z
ypsT:uLT
//等待子线程结束 y1+~IjY
//int count = 0; ee{8C~
//是否结束while循环 O;~dao
boolean breakWhile = false; nh+f,HtSt
. [5{
f iu?mb=*
while(!bStop) jwZBWt )5
{ kc-v(WIC
write_nPos(); G9P)Y#WB
Utility.sleep(500); pm}!?TL
breakWhile = true; j?'It`s
ET}Dh3A
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for(int i=0;i<nStartPos.length;i++) i-_ * 5%A
{ _T[m YY
if(!fileSplitterFetch.bDownOver) d}RR!i`<N
{ 4]3(Vyh`
breakWhile = false; 0s8w)%4$
break; J,j!
} l-RwCw4f
} G!3d!$t
if(breakWhile) #jNN?,ZK
break; 3erGTa[|q
&ZUV=q%g9n
& !I$
//count++; o$-!E(p
//if(count>4) XB'PEvh8
// siteStop(); by8~'?
} )I`Ma6bX
01" b9`jU
x-HN]quhe
System.err.println("文件下载结束！"); x)Ls(Xh+g
} "iY=1F"\R
catch(Exception e){e.printStackTrace ();} .#ASo!O5q
} @>sZ'M2mq
1O,<JrE+-
f/6,b&l,
//获得文件长度 CDTM<0`%
public long getFileSize() =vZF/r
{ jjrhl
int nFileLength = -1; sHQ82uX
try{ %\2w 1
URL url = new URL(siteInfoBean.getSSiteURL()); :gJ?3LwTf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I@<\DltPi
httpConnection.setRequestProperty("User-Agent","NetFox"); /"%(i#<)xs
"`4V^1
bI"_hvcFp
int responseCode=httpConnection.getResponseCode(); kL1StF#p
if(responseCode>=400) v8!Ts"
{ Wy`ve~y
processErrorCode(responseCode); :AM5EO
return -2; //-2 represent access is error rW(<[2vg
} V O= o)H\
YXr"
ht1d[
String sHeader; U4*Q;A#
^*=.Vuqy
w`$M}oX(
for(int i=1;;i++) 1$#{om9
{ fyE#8h_>4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +__PT4ps
//Utility.log(in.readLine()); ^<VJ8jk<
sHeader=httpConnection.getHeaderFieldKey(i); [|!A3o
if(sHeader!=null) _`(WX;sK
{ at-+%e
if(sHeader.equals("Content-Length")) ,=@%XMS
{ ?|;q=p`t-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vRQ7=N{3
break; ecRY,MN
} U'(@?]2<G
} QwSYjR:K
else shAoib?Kw:
break; H]x-s
} Lm{qFu
} $)O=3dNbo
catch(IOException e){e.printStackTrace ();} *VPjBzcH
catch(Exception e){e.printStackTrace ();} R@8pKCL.
B3V;
HDY2<Hzc
Utility.log(nFileLength); EDf"1b{PX
aF41?.s
,p\:Z3{ZH
return nFileLength; e(~9JP9
} ^L@2%}6b`
e: aa
\_w>I_=F
//保存下载信息（文件指针位置） 34gC[G=
private void write_nPos() `,lry7]
{ /Qnq,`z
try{ 5SNa~ kC&
output = new DataOutputStream(new FileOutputStream(tmpFile)); "A]Xe[oS
output.writeInt(nStartPos.length); p9`!.~[
for(int i=0;i<nStartPos.length;i++) -E(0}\
{ Glw_<ag[
// output.writeLong(nPos); Sd |=*X
output.writeLong(fileSplitterFetch.nStartPos); ._i|+[
output.writeLong(fileSplitterFetch.nEndPos); 15X.gx
} NlG~{rfI
output.close(); 1z5Oi u
} ;#Y'SK
catch(IOException e){e.printStackTrace ();} ?;0w1
catch(Exception e){e.printStackTrace ();} dz>2/'
} D,l&^diz
#{DX*;1m
u9zEhfg8
//读取保存的下载信息（文件指针位置） 5Y(<T~
private void read_nPos() <(c_[o/
{ 5mYX#//:
try{ iX|K4.Pz{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e>] gCa
int nCount = input.readInt(); =+z+`ot
nStartPos = new long[nCount]; Z.l4<
nEndPos = new long[nCount]; S<Os\/*
for(int i=0;i<nStartPos.length;i++) w$##GM=Tq
{ x,% %^(
nStartPos = input.readLong(); a7@':Rb n
nEndPos = input.readLong(); LN0pC}F
} ("r\3Mvs
input.close(); .V
} :2zga=)g
catch(IOException e){e.printStackTrace ();} BH"OphE
catch(Exception e){e.printStackTrace ();} o^ zrF
} y9)w(y!
6D&{+;
/f}!G
private void processErrorCode(int nErrorCode) je`Ysben
{ K!,T.qA&=
System.err.println("Error Code : " + nErrorCode); rLpfybu
} A+w'quXn
}Be;YIhG
Mm)yabP
//停止文件下载 !y\r.fm!A
public void siteStop() I?&/J4o:
{ 8v}B-cS
bStop = true; [. Db56
for(int i=0;i<nStartPos.length;i++) {)jTq??
fileSplitterFetch.splitterStop(); >'1[Bh
}] p9
?yc{@|
} v6M4KC2?
} y<g1q"F
//负责部分文件的抓取 0H/)wy2ym
**FileSplitterFetch.java d@XXqCR<
*/ U #C@&2
package NetFox; akA7))Q
SNJSRqWL/
dM=45$\q
import java.io.*; tiGBjTPt
import java.net.*; jP{&U&!i
7,lnfCm H
lsaA
public class FileSplitterFetch extends Thread { U EjP`
;aN_!! r
S"4eS,5L|
String sURL; //File URL g7"2}|qxo
long nStartPos; //File Snippet Start Position nSv@FT'~z
long nEndPos; //File Snippet End Position ZfMs6`Wv 1
int nThreadID; //Thread's ID KTq+JT u
boolean bDownOver = false; //Downing is over 6Hp+?mmh
boolean bStop = false; //Stop identical B[,AR"#b
FileAccessI fileAccessI = null; //File Access interface BPuum
\i'Z(1
M>_vsI^I'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k-Yli21-/|
{ 'eo/"~/*w
this.sURL = sURL; ;,}Dh/&E
this.nStartPos = nStart; CkV5PU
this.nEndPos = nEnd; Qhq' %LR
nThreadID = id; w^"IR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v YJ9G"E
} ?g9:xgkF ^
d9&
`/O AgV"`
public void run() jF}-dfe
{ L^jjf8_
while(nStartPos < nEndPos && !bStop) "Ccyj/
{ M#_|WL~
F8S>Ld
\%|Xf[AX
try{ PjD9D.
URL url = new URL(sURL); ;1HzY\d%<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q6,z 1A"
httpConnection.setRequestProperty("User-Agent","NetFox"); |h?2~D!+d
String sProperty = "bytes="+nStartPos+"-"; n$F~
httpConnection.setRequestProperty("RANGE",sProperty); Fw S>V2R
Utility.log(sProperty); uGv|!UQw
{Q}F.0Q
L>h|1ZK
InputStream input = httpConnection.getInputStream(); yQ)&u+r
//logResponseHead(httpConnection); A;<wv>T
gYCr,-_i
[j}JCmWY
byte[] b = new byte[1024]; _i_P@I<M|~
int nRead; " Lh&s<[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [l3ys
{ $nb.[si\
nStartPos += fileAccessI.write(b,0,nRead); Ptc+ypTu
//if(nThreadID == 1) -&COI-P8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XEnu0gr
} aeISb83Y|
}T0O~c{$i
PY;tu#W!%
Utility.log("Thread " + nThreadID + " is over!"); <.mH-Y5i
bDownOver = true; 9Ta0Li
//nPos = fileAccessI.write (b,0,nRead); dU#-;/}o
} CLTkyS)C
catch(Exception e){e.printStackTrace ();} ;=7K*npT
} 0k#7LubWZl
} *a\6X( ~
9O-2
QgI[#d{
//打印回应的头信息 y^"@$
public void logResponseHead(HttpURLConnection con) p- a{6<h
{ kU+|QBA@
for(int i=1;;i++) L R\LC6kM
{ pCDN9*0/
String header=con.getHeaderFieldKey(i); gW,hI>
if(header!=null) {#:31)P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n1JtY75#,/
Utility.log(header+" : "+con.getHeaderField(header)); j*5IRzK1%0
else $&=xw _
break; EJ>&\Iq
} fZezDm(Q
} 6Cz O ztn
qVKdc*R-
@)BO`;*$fF
public void splitterStop() WR3,woo
{ `sCn4-$8
bStop = true; |mP};&b
} ^$50[
5Yhcnwdm!
BZ=I/L
} {O9(<g
8Z0x*Ssk
@zC6`
/* {nbT$3=Zt
**FileAccess.java <)p.GAZ
*//文件访问(定位，写) Lo~;pvv
package NetFox; 1_<x%>zG
import java.io.*; 59O-"Sc[
s(nT7x+W
)Xh}N
public class FileAccessI implements Serializable{ o]~\u{o#.
-?-XO<I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g_1#if&
RandomAccessFile oSavedFile; <(q(5jG
long nPos; v,S5C
&s='$a;4
UWF \Vx*)b
public FileAccessI() throws IOException [Q0V5P~Q'
{ v!8=B21
this("",0); t&xoi7!$
} 8 ECX[fw
c3O/#*
F?|Efpzow?
public FileAccessI(String sName,long nPos) throws IOException *m}8L%<HT
{ X>Vc4n<}
oSavedFile = new RandomAccessFile(sName,"rw"); =w!ik9
this.nPos = nPos; \c -m\|
oSavedFile.seek(nPos); HiA E9
} `^Vd*
w.-x2Zg},
dgjK\pH`h
public synchronized int write(byte[] b,int nStart,int nLen) Cjx4vP
{ ;NR|Hi]
int n = -1; A<ds+0
try{ uYMn VE"
oSavedFile.write(b,nStart,nLen); Xj 1Oxm42
n = nLen; :YI5O/gsk?
} _6nAxm&x`%
catch(IOException e) u<Kowt<ci
{ UPI- j#yc
e.printStackTrace (); "5&"Ij,/
} ^o{{kju
tL$,]I$1+
0+e=s0s.
return n; <NMJkl-r8r
} v-tI`Qpb
H-PVV&r
.;]WcC<3
} pL"{Uqi
x ;|HT
:QGkYJ
/* oFj_o
**SiteInfoBean.java ^e8xg=8(
*/ -K'UXoU1
package NetFox; 8YFG*HSa
taE p
WR{m?neE_N
public class SiteInfoBean { fAgeF$9@
rO7_K>g?
u%~'+=
private String sSiteURL; //Site's URL rx2)uUbR
private String sFilePath; //Saved File's Path y:RW:D&
private String sFileName; //Saved File's Name F qH))2
private int nSplitter; //Count of Splited Downloading File ENuL!H>;*
C2}y#AI
gz~oQ l)zJ
public SiteInfoBean() WT'-.UX m
{//nSplitter的缺省值为5 )Ka-vX)D@
//default value of nSplitter is 5 S=_u3OH0
this("","","",5); cXPpxRXBD
} .; F<X\_
lo$G*LWu:
-qc'J<*^4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a9-Mc5^'n
{ NPK;
sSiteURL= sURL; ga;nM#/
sFilePath = sPath; Uj7YTB
sFileName = sName; k|/VNV( =0
this.nSplitter = nSpiltter; /oT~CB..
ZAr6RRv ^
H~Uf2A)C
} ,)1C"'
SE+hB
{Dpsr` &
public String getSSiteURL() ',r` )9o
{ .dU91> ~Ov
return sSiteURL; /o9it;
} NV* 2
kG/1
@P7'MiP]K
public void setSSiteURL(String value) (%X *b.n=
{ 1kvX#h&V
sSiteURL = value; FOQ-KP\=,
} )/jDt dI
gy}3ZA*F
cy8>M))c
public String getSFilePath() 8J3#(aBm
{ 3gUY13C}:p
return sFilePath; V *@q< rQ
} ^*}D*=>\
7Mh'x:p
28"1ONs3
public void setSFilePath(String value) f6Y?),`
{ sE?%;uBb
sFilePath = value; tg\Nm7I
} jlBsm'M<m
!igPyhi,hl
NCKR<!(
public String getSFileName() D,cD]tB2
{ v@{y}
return sFileName; bo=H-d|
} ~rV$.:%va
dHY@V>D'-
PA^*|^;Xh
public void setSFileName(String value) QZVyU8j3
{ ;5/Se"Nd
sFileName = value; nGVr\u9z
} 7KlL%\
8'Q+%{?1t
nOPB*{r|
public int getNSplitter() =78y*`L
{ .4a|^ vT
return nSplitter; jA,y.(mR
} Z?eTjkNS#
NOTG|\{
-U2Su|:\N8
public void setNSplitter(int nCount) 5S4Nx>
{ X?haHM#]
nSplitter = nCount; /RB%m8@;
} 7**zb"#y
} j0L%jz
(')t>B1Z
;j T{< Y
/* xQZOGq
**Utility.java %1{S{FB
*/ q?j7bp]
package NetFox; e)HFI|>
l iY/BkpH
@g[ijs\
public class Utility { Ov(k:"N
4m\Cc_:jO
#bd=G(o~6
public Utility() 1jx?zvE,
{ OFohyy(
Tcy9oYh!Pn
&5HI
} yFAUD ro
w_U#z(W3l
//线程睡眠 <@M5 C-hH
public static void sleep(int nSecond) ^h_rE |c
{ KYTXf+oh
try{ Zdrniae ah
Thread.sleep(nSecond); "I=Lbh-`
} -d?<t}a
catch(Exception e) ):Fg {7b]n
{ Wgf f+7k
e.printStackTrace (); 9vi+[3s/=;
} _&HFKpHQ
} HxR5&o
F~v0CBcAL
//日志 F4=X(P_6
public static void log(String sMsg) p_xJKQS
{ %5L~&W}^"
System.err.println(sMsg); l%V+]skS
} ."Pn[$'.
Ks3YrKk;p
"U9e)a0v
public static void log(int sMsg) ~e|E5[-i
{ <YCjo[(~
System.err.println(sMsg); h/5V~ :)
} ZXhNn<
} vmxS^_I
<DMm [V{
]Y,V)41gCE
/* 1^AQLOiRE1
**TestMethod.java +^J&x>5
*/ `_DA!
package NetFox; zq5N@dF
6oWFjeZ0
&#C|
public class TestMethod { cm!vuoB~~
iJZvVs',
*k\;G?
public TestMethod() L]YJ#5
{ ///xx/weblogic60b2_win.exe E\2f"s
try{ e<DcuF<ZS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kJ* N`=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); An]Vx<PD
SiteFileFetch fileFetch = new SiteFileFetch(bean); -Nr*na^H9#
fileFetch.start(); <}^p5|
} Cf 202pF3y
catch(Exception e){e.printStackTrace ();} P/S,dhs(
dRs\e(H'
1< b~="
} mJ8EiRSE
HII@Ed f?
#m{F*(%
public static void main(String[] args) U*EBH
{ 4tkb7D q
new TestMethod(); ,A#gF_8
} KsTE)@F:
} $LBgBH&z
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