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)); s,pg4nst56
} m8G/;V[x
for(int i=0;i<nEndPos.length-1;i++) (uy\~Zb
{ H<;~u:;8Q
nEndPos = nStartPos[i+1]; 'NCx<0*
} Zz]/4 4t
nEndPos[nEndPos.length-1] = nFileLength; }W(t>>
} s?&S<k-=fr
} JoZzX{eu"
rhX?\_7o
rx@i.+
//启动子线程 d2)]6)z6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k*C[-5&#
for(int i=0;i<nStartPos.length;i++) k7L4~W
{ YfMs~}h,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /[ft{:#&t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W7@Vma`
nStartPos,nEndPos,i); DRTT3;,N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yD`pUE$
fileSplitterFetch.start(); AxF$7J(
} \:'6_K
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h(3-/4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h?}S|>9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .cx9+;
nEndPos = " + nFileLength); J4z&J SY
// fileSplitterFetch[nPos.length-1].start(); )vg@Kc26
rY1jC\
:_nGh]%
//等待子线程结束 gS`Z>+V5!c
//int count = 0; -/*VR$c
//是否结束while循环 -7o-d-d F
boolean breakWhile = false; fA[T5<66
)7Qp9Fxo
'WBhW5@
while(!bStop) RzFxO
{ FFmXT/K"/j
write_nPos(); SJi;_bVf
Utility.sleep(500); hhI*2|i"L
breakWhile = true; D~`RLPMk
|lu@rN
jHA(mU)b
for(int i=0;i<nStartPos.length;i++) n!lE|if
{ *"6A>:rQs
if(!fileSplitterFetch.bDownOver) c?GV
{ g2rH"3sC
breakWhile = false; g2 mq?q(g
break; ]gF=I5jn]
} 6lkCLH
} 9i{(GO
if(breakWhile) Gc5mR9pV
break; +bb-uoZf
~3-+~y=o~
EQM[!g^a
//count++; w_LkS/
//if(count>4) >%n6n! "
// siteStop(); 4$ah~E>,t
} +>c%I&h}`
h=n\c6Q
9+.3GRt7
System.err.println("文件下载结束！"); Bi"cWO
} Z*v`kl
catch(Exception e){e.printStackTrace ();} *7#5pT~
} C8}=fa3u
w^7[4u4
LA(/UA3Izd
//获得文件长度 9'|_1Q.b^
public long getFileSize() ?[DVYP
{ W*n|T{n
int nFileLength = -1; ygK,t*T20
try{ 0wF)bQv1
URL url = new URL(siteInfoBean.getSSiteURL()); gh `_{l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J'L6^-gV
httpConnection.setRequestProperty("User-Agent","NetFox"); }We-sZ/w7r
b'ir$RL] c
8MBY3F
int responseCode=httpConnection.getResponseCode(); a\B?J
if(responseCode>=400) ldRq:M5z
{ ^.*zBrFx
processErrorCode(responseCode); 'I>geW?{QK
return -2; //-2 represent access is error yD0DPtti
} J$`5KbT3
>J:liB|(
]9wTAb
String sHeader; Zl.,pcL
<^ratz!-
3S%/>)k
for(int i=1;;i++) `?d` #)Ck
{ 3 [O+wVv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "od2i\
//Utility.log(in.readLine()); tQTjqy{K
sHeader=httpConnection.getHeaderFieldKey(i); X'xnJtk
if(sHeader!=null) H5CL0#I
{ S&Hgr_/}c
if(sHeader.equals("Content-Length")) x}{O9LiR
{ ~Ds3-#mMy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); EK\xc'6M
break; O6">Io5
} f'Oj01[
} w5t|C>
else }z2[w@M
break; Y+0GJuBf
} ~h3~<p#M`
} /HdjPxH
catch(IOException e){e.printStackTrace ();} #f_.
catch(Exception e){e.printStackTrace ();} oS<*\!&D
Sh:_YD^(
e`K{
Utility.log(nFileLength); j&q%@%Gm
(Dx p
4MCj*ok<
return nFileLength; M5N#xgR
} Ian+0 ?`e
oA;ZDO06r
N_l_^yD
//保存下载信息（文件指针位置） ss`Sl$
private void write_nPos() qTGi9OP6/
{ FJn.V1
try{ p@oz[017/J
output = new DataOutputStream(new FileOutputStream(tmpFile)); n(sseQ|\
output.writeInt(nStartPos.length); ;R$2+9
for(int i=0;i<nStartPos.length;i++) RSnBG"
{ gSe3S-Lt
// output.writeLong(nPos); COHook(:
output.writeLong(fileSplitterFetch.nStartPos); F!-%v5.y
output.writeLong(fileSplitterFetch.nEndPos); {+EnJ"
} F?qg?1vB|
output.close(); ,E"n7*6mr
} '1~;^rU
catch(IOException e){e.printStackTrace ();} Ko|gH]B'
catch(Exception e){e.printStackTrace ();} `]a0z|2'!
} 20I/En
e`Co ='
Of}C.N8
//读取保存的下载信息（文件指针位置） RrdLh z2N
private void read_nPos() OP\L
{ $oPc,zS-gL
try{ RYdI$&]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'X`W+=T$
int nCount = input.readInt(); [GcW*v
nStartPos = new long[nCount]; g8@F/$HY
nEndPos = new long[nCount]; \9`.jB~<
for(int i=0;i<nStartPos.length;i++) *Rxn3tR7
{ Rr}m(e=
nStartPos = input.readLong(); gMp' S
nEndPos = input.readLong(); oN`khS]_v0
} R*r"};
input.close(); Pc<0kQg
} uQ7lC~
catch(IOException e){e.printStackTrace ();} ?#RhHD
catch(Exception e){e.printStackTrace ();} DWN9_*{
} ncTMcu
M`E}1WNQ?]
"=V!-+*@G@
private void processErrorCode(int nErrorCode) 4um^7Ns)7
{ (6b0rqPF
System.err.println("Error Code : " + nErrorCode); dN7.W
} fB]NEx|o~
CTxP3a9]
d]MpE9@'v
//停止文件下载 G,<l}(tEG
public void siteStop() Z*-a=u%gl'
{ S)/548=`
bStop = true; :6/$/`I0W
for(int i=0;i<nStartPos.length;i++) Ty#sY'%
fileSplitterFetch.splitterStop(); |dDKO
ZT8LMPC
T|0d2aa
} f>|<5zm#<
} >]o>iOz;]
//负责部分文件的抓取 ) TRUx
**FileSplitterFetch.java \ FJ ae
*/ c _!!DEe7
package NetFox; ;--D?Gs]Qr
*||Q_tlz
TKgN31`
import java.io.*; qw>vu7/z
import java.net.*; "h|kf% W
\A)Pcc}7
5:C>:pAV
public class FileSplitterFetch extends Thread { >s1?rC
i0zrXaKV
K\59vtga
String sURL; //File URL ia3!&rZ
long nStartPos; //File Snippet Start Position rm-;Z<
long nEndPos; //File Snippet End Position zx*D)i5-
int nThreadID; //Thread's ID _O;4>
boolean bDownOver = false; //Downing is over o8v,178
boolean bStop = false; //Stop identical S_ UAz
FileAccessI fileAccessI = null; //File Access interface pf%;*
ael] {'h]
X8-x$07)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &]shBvzl^
{ /7fd"U$Lh
this.sURL = sURL; $RNHRA.
this.nStartPos = nStart; =Y5m% ,Bq
this.nEndPos = nEnd; =\oL'>q
nThreadID = id; 9v?@2sOoE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .U44p*I
} _:WNk(
D$*o}*mb
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public void run() rHk,OC
{ (|rf>=B+H
while(nStartPos < nEndPos && !bStop) s@{~8cHgU
{ f-ceDn
O&yAFiCd
k7;i^$@c
try{ BW}M/
URL url = new URL(sURL); VJFFH\!`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (DS"*4ty
httpConnection.setRequestProperty("User-Agent","NetFox"); *Ms"{+C
String sProperty = "bytes="+nStartPos+"-"; /&_q"y9
httpConnection.setRequestProperty("RANGE",sProperty); P=6d<no&<
Utility.log(sProperty); fW=<bf
C:sgT6
;AVIt!(L~V
InputStream input = httpConnection.getInputStream(); A:y^9+Da
//logResponseHead(httpConnection); T zS?WYF
](n)bF+ym
YW~ 9N
byte[] b = new byte[1024]; N$t<&5+
int nRead; h,&{m*q&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F?FfRzZ[
{ AZik:C"Q
nStartPos += fileAccessI.write(b,0,nRead); P~lU`.X}
//if(nThreadID == 1) N}#"o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |Bi7:w
} BUsxgs"),
m##!sF^k~J
y<nPZ<h
Utility.log("Thread " + nThreadID + " is over!"); n,s7!z/
bDownOver = true; >L "+8N6
//nPos = fileAccessI.write (b,0,nRead); xj8z*fC;
} [r Nd7-j <
catch(Exception e){e.printStackTrace ();} noz1W ]
} pJ1\@G
} EBL-+%J8
.w{Y3,dd>
=6 zK1Z
//打印回应的头信息 [742s]j
public void logResponseHead(HttpURLConnection con) OXKV6r6f
{ <ty]z!B
for(int i=1;;i++) j+ L:Ao
{ `x>6Wk1
String header=con.getHeaderFieldKey(i); +C,/BuG
if(header!=null) 0,@^<G8?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Svo\+S
Utility.log(header+" : "+con.getHeaderField(header)); /joY? T
else nnT#S
break; +%klS `_
} ,g0t&jITo
} R)SY#*Y
<z#Fj`2{
-L6CEe
public void splitterStop() T2rBH]5
{ iV#A-9
bStop = true; [\h?mlG?
} PP!-*~F0Jr
AX1!<K
]s)Y">6
} oqbz!dM(Z
f2M*]{N
*2vp2xMA@
/* ~G=E Q]a
**FileAccess.java v)gMNzt
*//文件访问(定位，写) s>\^dtG7
package NetFox; GBpdj}2=
import java.io.*; n=$ne2/
$-t@=N@vO?
q`L)^In"
public class FileAccessI implements Serializable{ H-u SdT
d2gYBqag
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rMjb,2*rC7
RandomAccessFile oSavedFile; Rmn{Vui9\
long nPos; r7?nHF
o37oRv]
' i5KRFy-
public FileAccessI() throws IOException $YY{|8@kjv
{ 4<E <sD
this("",0); -gt?5H h
} oyk&]'>
.b<W*4{j0H
:wg=H
public FileAccessI(String sName,long nPos) throws IOException * ]bB7
{ z6d0Y$A G
oSavedFile = new RandomAccessFile(sName,"rw"); %3t;[$n#
this.nPos = nPos; 8>x'. 8
oSavedFile.seek(nPos); L1g0Dd\Ox
} LdNpb;*
s7:H
puWMgvv
public synchronized int write(byte[] b,int nStart,int nLen) TKGaGMx6@
{ TKAs@X,t
int n = -1; ^^B_z|;Aa
try{ Y[R>?w
oSavedFile.write(b,nStart,nLen); qAbmQ{|w
n = nLen; fXl2i]L(^B
} C%]qK(9vvd
catch(IOException e) #s\kF *
{ SRk!HuXh
e.printStackTrace (); 4~FRE)8
} $2i@@#g8
L'aB/5_%
tH *|
return n; vbtZ5Gm
} S|LY U!IWZ
$^?VyHXvY
p19@to5l
} TKsP#Dt/
q%$p56\?3
>C6S2ISSz
/* 2@z.ory.
**SiteInfoBean.java Rj>A",
*/ uG6.(A1LM
package NetFox; yOKzw~;0%
VzHrKI
H6jt[
public class SiteInfoBean { x lqP%
o'(BL:8s
6g"h}p\{S
private String sSiteURL; //Site's URL ;i?2^xe^~c
private String sFilePath; //Saved File's Path /JC1o&z_T
private String sFileName; //Saved File's Name ?vAhDD5
private int nSplitter; //Count of Splited Downloading File eQ8t.~5;-
dlCYdwP
i}v.x
public SiteInfoBean() ,i<cst)$u
{//nSplitter的缺省值为5 hf2bM `d
//default value of nSplitter is 5 Avi_]h&
this("","","",5); 6XU p$Pd(
} BU??}{
Gs3V]qbEP
6G"UXNa,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Xz)F-C27h
{ #Mk:4
sSiteURL= sURL; L)F4)VL
sFilePath = sPath; H2#o X
sFileName = sName; 9Scg:}Nj
this.nSplitter = nSpiltter; QQV8Vlv"
=MJB:
~XuV:K3
} =QtFJ9\
ug ;Xoh5w
gVzIEE25
public String getSSiteURL() `t)9u^[<(
{ y'4Qt.1ukN
return sSiteURL; Q/0gd? U?
} @d 7V@F0d
c$&({Z{1
YOGj__:
public void setSSiteURL(String value) 0\ (:y^X
{ E JuTv%Y8
sSiteURL = value; S-gO
} {dpDQP +!
sHk>ek]2I
P3|s}&
public String getSFilePath() h ka_Fo
{ a <?~1pWtc
return sFilePath; vFntzN>#
} a oU"
jED.0,+K!
;e5PoLc
public void setSFilePath(String value) T~Bj],k_
{ (,QWK08
sFilePath = value; BPt? 3tC
} -mRgB"8
oU\7%gQ
F/>\uzu
public String getSFileName() |%XTy7^a
{ $'Mf$h
return sFileName; 7G-?^
} `{Q'iydU
bK~Toz<k
^&1O:G*"
public void setSFileName(String value) |H_WY#
{ n^ fUKi*;
sFileName = value; N=2T~M 1
} C,l,fT
LPJ7V`!k
b=:ud[h
public int getNSplitter() 04;s@\yX4
{ X]@"ZV[
return nSplitter; o|z@h][(l(
} ={oNY.(Q
J$1H3#VVG
\b(&-=(
public void setNSplitter(int nCount) ,7)hrA$(
{ Yn="vpM1
nSplitter = nCount; d:K\W[$Bz
} F.$z7ee@
} }p2iF2g9`
Gg9MAK\C9
=cjO]
/* ]Rxo}A
**Utility.java V)/J2-w
*/ ,/b!Xm:
package NetFox; qq&U)-`
H@xS<=:lM
3_XLx{["'
public class Utility { bT2G G
.UL2(0
>iOf3I-ATt
public Utility() <nbklo
{ * CR#D}F
N?vb^?
LPt9+sauf1
} oHx:["F
bGeIb-|(
//线程睡眠 3jxC}xz)
public static void sleep(int nSecond) BK%B[f*[OA
{ Dbn344s
try{ #'s$6gT=
Thread.sleep(nSecond); ~KS@Ulrox
} Zhfg
catch(Exception e) m- <y|3
{ a&b/C*R_
e.printStackTrace (); NLL"~
} Ju47}t%HB
} VM\R-[
~bb6NP;'L
//日志 P5_Ajb(@'
public static void log(String sMsg) { %X2K
{ lF!PiL
System.err.println(sMsg); vNs%e/~vj
} @L!^2v
`~u=[}w
cHFW"g78
public static void log(int sMsg) )>FAtE
{ "PI;/(kR
System.err.println(sMsg); o( zez
} gE\ ^ vaB
} '1b 1N5~
jC>ZMy8U)4
X13+n2^8]
/* lUEbxN
**TestMethod.java Nz`8)Le
*/ "crR{OjE"
package NetFox; T/P\j0hR
q\o#<'F1J
AEyD?^?
public class TestMethod { x7zc3%T's
]z^jz#>um&
cl^UFlf[
public TestMethod() V[/9?5pM
{ ///xx/weblogic60b2_win.exe ]ouoRlb/
try{ u$aK19K/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Cst1nGPL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -6- sI
SiteFileFetch fileFetch = new SiteFileFetch(bean); '69)m~B0a
fileFetch.start(); M,H8ZO:R
} _r3Y$^!U
catch(Exception e){e.printStackTrace ();} 2v ~8fr4
!FP ]
a^J(TW/
} ]C,j80+pK
$mGzJ4&
2Cp4aTGv#
public static void main(String[] args) 3pWav 1"
{ L.@$rFhA
new TestMethod(); |9S8sfw
} R|qrK
} [m:cO6DM,
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