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)); HQ ^> ~
} }4 P@`>e/`
for(int i=0;i<nEndPos.length-1;i++) IEjKI"
{ H_vOZ0
nEndPos = nStartPos[i+1]; p\b:uy6#
} "xdXHuX
nEndPos[nEndPos.length-1] = nFileLength; >77 /e@
} u23^* -
} 6>SP5|GG
lmQ!q>N
M2%<4(UwI
//启动子线程 ]^/:Xsk$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E/Eny5
for(int i=0;i<nStartPos.length;i++) IAhyGD{b
{ YJ.'Yc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #B;`T[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -"<H$
nStartPos,nEndPos,i); ATk>:^n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `c(,_oa{
fileSplitterFetch.start(); .e"De-u
} b4S7Q"g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ) m%ghpX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J$j&j`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !gW$A-XD
nEndPos = " + nFileLength); pj?+cy v~
// fileSplitterFetch[nPos.length-1].start(); 3yZtyXRPn
(ZT*EFhb(
ol:,02E&
//等待子线程结束 P\*-n"
//int count = 0; \*v}IO>2})
//是否结束while循环 S2;{)"mS
boolean breakWhile = false; ,BOB &u
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no)Spo'
while(!bStop) c{V0]A9VF
{ +\\*Iy'xK
write_nPos(); e7>)Z
Utility.sleep(500); ()}O|JL:K
breakWhile = true; ;)u}`4~L
UVxE~801Y
Ajs<a(,6
for(int i=0;i<nStartPos.length;i++) EYcvD^!1g
{ yQM7QLbTk
if(!fileSplitterFetch.bDownOver) 8y/YX
{ {ZY^tTsY
breakWhile = false; $/Zsy6q:
break; zf5s\w.4
} _+wv3? c"
} R]m`v: 9
if(breakWhile) FWq6e,
break; 0r_8/|N#
/^P^K
;!Ojb
//count++; X+?*Tw!\
//if(count>4) B#B$w_z
// siteStop(); J55K+
} A WMR0I
Haaungb"
<@A/`3_O)
System.err.println("文件下载结束！"); "z=A=~~<{
} %0Ulh6g;Dt
catch(Exception e){e.printStackTrace ();} h" P4
} ?G*XZ0u~
I&q:w\\z8|
*~lD;{2
//获得文件长度 ;]i&AAbj
public long getFileSize() RR75ke[Hs
{ DSizr4R
int nFileLength = -1; *;,=x<
try{ fP&F$"o8
URL url = new URL(siteInfoBean.getSSiteURL()); @zT.&1;`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n-}:D<\7
httpConnection.setRequestProperty("User-Agent","NetFox"); yodJGGAzk
4+$<G/K
;=5V)1~i1;
int responseCode=httpConnection.getResponseCode(); NQ'^z
if(responseCode>=400) B5 C]4
{ ?0DCjh8We
processErrorCode(responseCode); #fk)Y1
return -2; //-2 represent access is error ,B5Ptf#
} 0{BPT>'
23_<u]V
c^6v7wT5
String sHeader; a_`E'BkgU
H{\tQ->(2
*O)_D bj
for(int i=1;;i++) 8v*>~E/0
{ >#$(M5&}-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fh b&_T
//Utility.log(in.readLine()); p<Ah50!B
sHeader=httpConnection.getHeaderFieldKey(i); p27A#Uu2}
if(sHeader!=null) i74^J+xk
{ wTf0O@``6H
if(sHeader.equals("Content-Length")) UacN'Rat
{ E:D1ZV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SV<*qz
break; hIXGfvUy
} QTz{ZNi!
} U4 m[@wF
else ;}A#ws_CD_
break; ]vXIj0:
} ]n _-
} kZU8s'C
catch(IOException e){e.printStackTrace ();} `]LaX&u
catch(Exception e){e.printStackTrace ();} >BrxJw#M
E&{*{u4
(e=ksah3>
Utility.log(nFileLength); s|pb0
~XsS00TL`G
~BERs;4
return nFileLength; \xDu#/^
} [9BlP
6zRJ5uI,/
YUT"A{L
//保存下载信息（文件指针位置） ,h#!!j\j6
private void write_nPos() W#u}d2mP
{ >u*woNw(XM
try{ d=oOMXYa
output = new DataOutputStream(new FileOutputStream(tmpFile)); I%e7:cs>
output.writeInt(nStartPos.length); JV36@DVQ
for(int i=0;i<nStartPos.length;i++) c5;YKON
{ cuq7eMG6z
// output.writeLong(nPos); Y@9L8XNP>
output.writeLong(fileSplitterFetch.nStartPos); TbIM{X
output.writeLong(fileSplitterFetch.nEndPos); nd3]&occ
} x^+ C[%
output.close(); ~e 6yaX8S
} O.&6J/
catch(IOException e){e.printStackTrace ();} yZ0;\Tr*J
catch(Exception e){e.printStackTrace ();} @ RTQJ+ms
} Pu/0<Orp7
}td+F&l($V
UM|GX
//读取保存的下载信息（文件指针位置） Jgtvia
private void read_nPos() 2mu~hJ
{ f#eTi&w
try{ AA>5h<NM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~q4DePVE
int nCount = input.readInt(); *VHBTO9
nStartPos = new long[nCount]; 4TwU0N+>
nEndPos = new long[nCount]; rJ\A)O+Mq(
for(int i=0;i<nStartPos.length;i++) "*+epC|ks
{ h,FP,w;G
nStartPos = input.readLong(); +}mj6I
nEndPos = input.readLong(); K8|6r|x
} g?`D8
input.close(); II>X6
} xBgf)'W_Z
catch(IOException e){e.printStackTrace ();} y^;qT_)#
catch(Exception e){e.printStackTrace ();} A'[A!NL%
} :vurU$\
^3=8*Xr
3C_g)5 _:
private void processErrorCode(int nErrorCode) )@R:$l86
{ }^`{YD
System.err.println("Error Code : " + nErrorCode); Gk[P-%%b /
} 3-o ]H'6
Cf`UMQ a
~{^A&#P
//停止文件下载 >x2T'
public void siteStop() s3J T1TX
{ 2i,Jnv=sR
bStop = true; aj(M{gFq~
for(int i=0;i<nStartPos.length;i++) WCR+ZXI?1
fileSplitterFetch.splitterStop(); *k+QX
X@~sIUXx9
_xUhDu%
} JiI(?I
} Z NCq/
//负责部分文件的抓取 yt!K|g
**FileSplitterFetch.java B@iIj<p~
*/ -F8%U:2a
package NetFox; A]H+rxg
a#uJzYB0
Jc:G7}j6
import java.io.*; *,'"\n
import java.net.*; DU 8)c$
ioa 1n=j
?7G[`@^Y
public class FileSplitterFetch extends Thread { c$e~O-OVD?
KJ9~"v
U]R7=
String sURL; //File URL l" sR\`~
long nStartPos; //File Snippet Start Position Z<&: W8n
long nEndPos; //File Snippet End Position e;!<3b
int nThreadID; //Thread's ID 8V}c(2m
boolean bDownOver = false; //Downing is over (qPZEZKx
boolean bStop = false; //Stop identical 8uI^ B
FileAccessI fileAccessI = null; //File Access interface l
9R ugkGy
dDm<'30?*v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OmoY] 8N}
{ .Dx]wv
this.sURL = sURL; S:1! )7
this.nStartPos = nStart; Pc4sReo'
this.nEndPos = nEnd; Nm;ka&'
nThreadID = id; 4e%SF|(Y'h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5@v!wms
} ~&yaIuW<
Eydk645:3
@NyCMe;]
public void run() ;c;;cJc!
{ wwpvmb
while(nStartPos < nEndPos && !bStop) oa9T3gQ?
{ -7pZRnv
9k*'5(D4S
F`38sq
try{ E4{^[=}
URL url = new URL(sURL); `q5*VqIhs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QTLOP~^
httpConnection.setRequestProperty("User-Agent","NetFox"); >G-D& A+
String sProperty = "bytes="+nStartPos+"-"; SgY>$gP9S
httpConnection.setRequestProperty("RANGE",sProperty); YE^|G,]
Utility.log(sProperty); Pd@?(WQ
GQ[\R&]q<
Y)a 7osML
InputStream input = httpConnection.getInputStream(); 1$ l3-x
//logResponseHead(httpConnection); `Y(/G"]
e8gD(T
f|< *2Mk
byte[] b = new byte[1024]; t=yM}#r$
int nRead; +q=/}|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y\@XW*_?
{ 0<P -`|X
nStartPos += fileAccessI.write(b,0,nRead); R"82=">v
//if(nThreadID == 1) RQh4RUm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); icnp^2P
} $:<KG&Br
Tlf G"HzZ%
R_Z H+@O
Utility.log("Thread " + nThreadID + " is over!"); N}^\$sVu_
bDownOver = true; G,$jU9 f
//nPos = fileAccessI.write (b,0,nRead); 4K4?Q+?
} .IG(Y!cB
catch(Exception e){e.printStackTrace ();} mk0rAN
} N2x\O~7
} -ff*,b$Q/
#PFf`7b,z
U`:$1*(`
//打印回应的头信息 \6sp"KqP
public void logResponseHead(HttpURLConnection con) eR;cl$
{ RE*SdazY?
for(int i=1;;i++) #^eviF8
{ 3 D+dM0wM
String header=con.getHeaderFieldKey(i); >S!QvyM(V
if(header!=null) ^Ji5)c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,c7 8O8|
Utility.log(header+" : "+con.getHeaderField(header)); rt."P20T
else Z!ub`coV[
break; & }}o9
} ,H.q%!{h_
} q5QYp
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public void splitterStop() #Ok*Or
{ *xt3mv/<z
bStop = true; OHH wcJ7N
} -,p(PK
&%INfl>o7.
x==%BBnO%
} a[t2TjB
~KCOCtiD
o,u-%
/* Q;`#ujxL
**FileAccess.java CFn!P;.!
*//文件访问(定位，写) 7]G3yt->
package NetFox; X_"TG;*$
import java.io.*; &{"aD&
;JDxl-~
V~ZAs+(2Z
public class FileAccessI implements Serializable{ up`!r;5-
{6A3?q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Rsqb<+7
RandomAccessFile oSavedFile; ULAAY$o@5
long nPos; rr2|xL?+u
@-)?2CH[8
>Ei_##
public FileAccessI() throws IOException 4Yx?75/
{ .3!=]=
this("",0); >H?8?a D
} rsA K0R+
HPm12&8,
C:zK{+
public FileAccessI(String sName,long nPos) throws IOException FhS:.
{ Qnph?t>
oSavedFile = new RandomAccessFile(sName,"rw"); [,$] %|6wt
this.nPos = nPos; 2et7Vw
oSavedFile.seek(nPos); MyAi)Mz~o
} Xb3z<r
L)J0TSh
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public synchronized int write(byte[] b,int nStart,int nLen) PJS\> N&u
{ =K}5 fe
int n = -1; IIs'm!"Y>
try{ A2g+m
oSavedFile.write(b,nStart,nLen); g!cTG-bh>J
n = nLen; TDk'
} iIA&\'|;i
catch(IOException e) '$;S?6$eW
{ 5c!~WckbJ
e.printStackTrace (); 9SXFiZA(r
} DNC2]kS<
8"Hy'JA$O
{Jwh .bJ
return n; tLJ"] D1w
} V-Oy<
iLNKC'
x{j|Tf3,G
} m "h{HgJd
seB ^o}
a9`E&Q}z
/* v&D^N9hy9
**SiteInfoBean.java tc.R(F96
*/ VE6 V^6SL
package NetFox; vzd1:'^t
d.3-@^P
X@2[!%nm
public class SiteInfoBean { I_oJx
(Xi?Y/
YJ3aJ^m#E
private String sSiteURL; //Site's URL #Huvn4x
private String sFilePath; //Saved File's Path :na9PW`TC
private String sFileName; //Saved File's Name bM;==W
private int nSplitter; //Count of Splited Downloading File -uHD| }
s(o{SC'tt
7H %>\^A^
public SiteInfoBean() DKx8<yEky
{//nSplitter的缺省值为5 L Me{5H
//default value of nSplitter is 5 z}&?^YU*)`
this("","","",5); L#1YR}m
} ]<V[H
~DPjTR
D .oX>L#:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^y]CHr
{ o['HiX
sSiteURL= sURL; aqSHo2]DX9
sFilePath = sPath; ^OnU;8IC
sFileName = sName; \!Cix}}1
this.nSplitter = nSpiltter; Gt3V}"B3\
DpI)qg#>V
n*D-01vYP
} ) wtVFG
>7[. {Y
3Un q 9
public String getSSiteURL() n,q+EZd
{ }1VxMx@
return sSiteURL; ]d=SkOq
} e)]9u$x
k7z;^:
*NHBwXg+
public void setSSiteURL(String value) ;P3sDN
{ jCa%(2~iQ7
sSiteURL = value; !o1{. V9q
} =UE/GTbl
G?AZ%Yx
ze@NqCF
public String getSFilePath() aVNBF`
{ DK;p6_tT
return sFilePath; D~E1hr&Vd>
} a|Io)Qhr
tpOMKh.`
h,o/(GNnW
public void setSFilePath(String value) j6]+fo&3
{ +P:xB0Tm D
sFilePath = value; YBqu7&
} uLX5khQ
l=,\ h&
2oyTS*2u_&
public String getSFileName() >qk[/\^O
{ #Mkwd5S|L
return sFileName; [%7y !XD
} Fa:fBs{
(99P9\[p
|\;oFuCv##
public void setSFileName(String value) +[Cdd{2
{ /`McKYIP
sFileName = value; K<TVp;N
} WDQtj$e+
#RT}-H
=@q 9,H
public int getNSplitter() q<Gn@xc'
{ e=ZwhRP
return nSplitter; J6J[\
} bL soKe
onL&lE
AlT41v~6
public void setNSplitter(int nCount) t[*;v
{ o8Vtxnkg
nSplitter = nCount; u>SGa @R)
} _ZX"gHx
} G|MjKe4}
H'7AIY}
q_S`@2Dzz,
/* S81Z\=eK
**Utility.java Ww-%s9N<
*/ #2l6'gWE0
package NetFox; Fb#.Gg9b>
*W aL}i(P1
GO0Spf_Gh
public class Utility { E]$YM5
Jf6uE?.
Elthxj
public Utility() 9 f$S4O5
{ 8fA9yQ8
oE@{h$=
tgoOzk^
} AE0d0Y~9
'NCxVbyYD
//线程睡眠 yZkHBG4
public static void sleep(int nSecond) e[_W( v
{ ,Fo7E
try{ $Lg%CY
Thread.sleep(nSecond); y Nb&;E7 H
} /xf4*zr
catch(Exception e) :a$ZYyD
{ /!J1}S
e.printStackTrace (); vl59|W6
} b*$/(2"m
} ~3-2Iu^F
6!P];3&o\A
//日志 NCbl|v=
public static void log(String sMsg) )#ze
{ 3S='/^l
System.err.println(sMsg); w}n:_e
} ]yu,YZ@7
L$zI_ z
!#cZ!
public static void log(int sMsg) KQ'fp:5|/@
{ jCdKau&9
System.err.println(sMsg); HRS|VC$tz
} SjgF&LD
} *4}lV8
4 4%jz-m
k#"Pv"
/* 5<Mht6"H
**TestMethod.java _\yrR.HIa
*/ h $)thW
package NetFox; LX A1rgUWT
yH_L<n
N!" ]e*q
public class TestMethod { :()(P9?
pcw!e_"+
mw}obblR
public TestMethod() JHpoW}7QB
{ ///xx/weblogic60b2_win.exe pL`snVz
try{ 2{naSiaq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KI(9TI*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V+M2Gf
SiteFileFetch fileFetch = new SiteFileFetch(bean); "o#N6Qu71
fileFetch.start(); -f?Rr:#
} +wd} '4)
catch(Exception e){e.printStackTrace ();} )Y':u_Lo
),`MAevp
bqY}t. Y&"
} 0[6llcuj
Fs_,RXW"
7kpCBLM(}
public static void main(String[] args) 8>q:Q<BB2
{ ]PdpC"
new TestMethod(); BcV;EEi
} Yh/-6wg
} $$YLAgO4
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