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)); I\)N\move
} +# A|Zp<
for(int i=0;i<nEndPos.length-1;i++) jh-kCF
{ <:H
nEndPos = nStartPos[i+1]; X@G[=Rs
} ZO]E@?Oav
nEndPos[nEndPos.length-1] = nFileLength; | H5Ync[s
} _p?I{1O
} 3<yCe%I:
ggzAU6J
P'KY.TjWb
//启动子线程 XWJ0=t&}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _y.mpX&
for(int i=0;i<nStartPos.length;i++) Ni/|C19Z
{ jAsh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vQE` c@^{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .kz(V5
nStartPos,nEndPos,i); (p}9^Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :a#|
fileSplitterFetch.start(); #zh6=.,7
} DWHOSXA4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S;G"L$&\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 75' Ua$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;g!xQvcR
nEndPos = " + nFileLength); 8Fyc#Xo8
// fileSplitterFetch[nPos.length-1].start(); B>c[Zg1
](idf(j
99=[>Ck)G
//等待子线程结束 GA}hp%
//int count = 0; kjQIagw
//是否结束while循环 })Ix.!p
boolean breakWhile = false; eU<]h>2
w/)e2CH
;w>Q{z
while(!bStop) !^rITiy
{ gt(X!iN]
write_nPos(); Ss*LgK_
Utility.sleep(500); m(Pz7U.Q
breakWhile = true; 3g4vpKg6c
*=r@vQ
O p!
for(int i=0;i<nStartPos.length;i++) <<~lV5
{ ^*j[&:d
if(!fileSplitterFetch.bDownOver) j58Dki->.
{ PkZf(=-X
breakWhile = false; 6T5A31 Q
break; {3_Ffsg`
} fwz5{>ON]
} CYY X\^hA
if(breakWhile) 7cJO)cm0'
break; !c3Qcva
vgd}09y
woC FN1W
//count++; mRix0XBI~
//if(count>4) e\+~
// siteStop(); wt3Z?Pb
} T/X?ZK(T
3(XHF3q
[v>Z(
System.err.println("文件下载结束！"); S:"z<O
} Vb"T],N1m
catch(Exception e){e.printStackTrace ();} N P0Hgd
} k1@ A'n
wjw<@A9
l=<F1Lz
//获得文件长度 R oF
public long getFileSize() , .NG.Q4f
{ N23+1h
int nFileLength = -1; B[2h
try{ _ cHV3cz
URL url = new URL(siteInfoBean.getSSiteURL()); Dg];(c+/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 96([V|5K
httpConnection.setRequestProperty("User-Agent","NetFox"); h<!khWFS
e2_r0I^C
%$!R]B)
int responseCode=httpConnection.getResponseCode(); 9Le/'ovq
if(responseCode>=400) n8y,{|
{ R-0_226
processErrorCode(responseCode); 071E%u,
return -2; //-2 represent access is error xhp-4
} 6O[wVaC1u
C$]%1<-Iv]
,sQ0atk7ma
String sHeader; Ra15d^
o 0cc+
H8Z Z@@ qm
for(int i=1;;i++) d~xU?)n)
{ LbmB([p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wb}N-8x
//Utility.log(in.readLine()); cxF?&0[mY
sHeader=httpConnection.getHeaderFieldKey(i); UVQa af
if(sHeader!=null) %RK\Hz2q3
{ k(vEp]
if(sHeader.equals("Content-Length")) o )}<
{ ytcG6WN3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); el*pYI
break; W> -E.#!_
} 6@Z'fT4
} s5Bmv\e.i5
else j@_) F^12
break; W;)FNP|MT
} @{$Cv"6769
} \Z7([Gh
catch(IOException e){e.printStackTrace ();} o\:f9JL
catch(Exception e){e.printStackTrace ();} =-s20mdj
(fI&(";t
U!-+v:SF
Utility.log(nFileLength); "3>*i!i
3I{ta/(
)su <Ji*
return nFileLength; /B#lju!
} *~lgU4
K {1ZaEH
>[P7Zlwv4
//保存下载信息（文件指针位置） ws=9u-
private void write_nPos() p9] 7g%
{ 2ZzD^:V[}
try{ t5B|c<Hb\
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7)6Yfa]I%
output.writeInt(nStartPos.length); [E :`jY
for(int i=0;i<nStartPos.length;i++) h9OL%n 7m'
{ Gk]qE]hi
// output.writeLong(nPos); E(4lu%
output.writeLong(fileSplitterFetch.nStartPos); qzbkxQu]g
output.writeLong(fileSplitterFetch.nEndPos); ?GD?J(S
} gp&& c,
output.close(); Hk~ gcG
} :`"T Eif
catch(IOException e){e.printStackTrace ();} +` Y ?-
catch(Exception e){e.printStackTrace ();} Ev|{~U
} EwBN+v;)
=rO>b{,hs
P@S;>t{TD
//读取保存的下载信息（文件指针位置） 8KELN(o$ 7
private void read_nPos() r/$)c_x`
{ 22|M{
try{ LXfeXWw?,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ';CuJXAj
int nCount = input.readInt(); i7!mMO8]
nStartPos = new long[nCount]; Y" +1,?yH
nEndPos = new long[nCount]; g!)LhE
for(int i=0;i<nStartPos.length;i++) 08n%% F
{ P)j9\ muc
nStartPos = input.readLong(); zhm!sMlO
nEndPos = input.readLong(); MfpWow-#{
} V1b_z
input.close(); O> ^~SO
} D>#v 6XI
catch(IOException e){e.printStackTrace ();} VOK$;s'9}
catch(Exception e){e.printStackTrace ();} f;XsShxr
} \t(r@qq
f]6`GsE
[W|7r n,q
private void processErrorCode(int nErrorCode) bz@=zLBt
{ 7'/2:"
System.err.println("Error Code : " + nErrorCode); WUK.>eM0
} A%8`zR
l|tp0[
&*:)5F5
//停止文件下载 7LZb*+>
public void siteStop() y<x_v )k-
{ JO6vzoS3
bStop = true; C`T5d
for(int i=0;i<nStartPos.length;i++) h/bYtE
fileSplitterFetch.splitterStop(); ?UhAjtYIS
|iJZC
}/}`onRZ
} eHyuO)(xH1
} h+u|MdOY\
//负责部分文件的抓取 ez:o9)N4
**FileSplitterFetch.java y^|3]G3
*/ j%y+W{Q[
package NetFox; hA1hE?c`
vc{]c }
f I-"8f0_
import java.io.*; l'lDzB+.*
import java.net.*; #_L&
#cF8)GC
.lj!~_
public class FileSplitterFetch extends Thread { G]DN!7]@g
eV=sDx
./*,Thc
String sURL; //File URL >Pd23TsN
long nStartPos; //File Snippet Start Position T:~W.3
long nEndPos; //File Snippet End Position (mD:[|.
int nThreadID; //Thread's ID tsC|R~wW
boolean bDownOver = false; //Downing is over eKti+n.
boolean bStop = false; //Stop identical 2DqHqq9m
FileAccessI fileAccessI = null; //File Access interface 5$Q`P',*Ua
%c2i.E/G
"/-v 9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x[@3;_'K
{ QAnfxt6
this.sURL = sURL; R/xCS.yl}
this.nStartPos = nStart; {Qmb!`F
this.nEndPos = nEnd; uqeWdj*Y
nThreadID = id; [Et\~'2w8=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k)' z<EL6c
} CIvT5^}
7Bd_/A($
'R5l =Wf
public void run() nln[V$
{ HZ4 ^T7G
while(nStartPos < nEndPos && !bStop) _7HJ'
{ OiEaVPSI;
`rJ ~*7-
ly5L-=Xb
try{ M@[gT?mv1
URL url = new URL(sURL); $ rnr;V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q8v!{Os+#
httpConnection.setRequestProperty("User-Agent","NetFox"); Guc^gq}
String sProperty = "bytes="+nStartPos+"-"; /j\TmcnU^
httpConnection.setRequestProperty("RANGE",sProperty); {#Cm> @')
Utility.log(sProperty); /[dAgxL
E004"E<E
8_$2aqr
InputStream input = httpConnection.getInputStream(); k8>^dZub
//logResponseHead(httpConnection); J0bs$
\)kAhKtG
~'\u:Imuo
byte[] b = new byte[1024]; gy`qEY~B&
int nRead; HW,55#yG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JY8pV+q @=
{ ]h$TgX
nStartPos += fileAccessI.write(b,0,nRead); p5t#d)
//if(nThreadID == 1) w.-i !Ls
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h!%`odl%
} v!C+W$,T
Gw,kC{:C
o[6"XJ
Utility.log("Thread " + nThreadID + " is over!"); XYTcG;_z
bDownOver = true; HhH'\-[t
//nPos = fileAccessI.write (b,0,nRead); D+PUi!
} Jl,x~d
catch(Exception e){e.printStackTrace ();} XKIJ6M~5k
} DdBrJx
} >G7U7R}R
S6Pb V}
..mz!:Zs0
//打印回应的头信息 _J;a[Ky+[
public void logResponseHead(HttpURLConnection con) Hf|:A(vCx
{ w2AWdO6
for(int i=1;;i++) R;2 -/MT-
{ 7Wn]l!
String header=con.getHeaderFieldKey(i); r5wXuA,Um
if(header!=null) %z(=GcWm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X/749"23
Utility.log(header+" : "+con.getHeaderField(header)); 7s3<}
else Nuq/_x
break; W)O'(D
} 6E4L4Vb
} JwVv+9hh
th|Q NG
aX:$Q }S
public void splitterStop() 6* w;xf
{ w Vmy`OV/
bStop = true; nzDY!Y
} mn` Ae=
HEN9D/O=
U%l{>*q
} .C?gnOq
,r4af<
a@1gMZc*
/* `rQl{$9IC
**FileAccess.java ? GW3E
*//文件访问(定位，写) m!(K
package NetFox; +R$KEGu~0Y
import java.io.*; Ne_>%P|I_
')<$AMy1
xy>mM"DOH
public class FileAccessI implements Serializable{ FFGTIT# {"
(^\i(cfu6Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '5\1uB PKW
RandomAccessFile oSavedFile; +[+Jd)Z
long nPos; _Z&R'`kg
;_*F [ }w
K)OlCpHc
public FileAccessI() throws IOException %Kp}Wo6
{ (FHh,y~v
this("",0); )cXc"aj@s
} z>~3*a9&
krU2S-
|{Q,,<C
public FileAccessI(String sName,long nPos) throws IOException Gx)D~7lz
{ P]GGnT(!
oSavedFile = new RandomAccessFile(sName,"rw"); ]f?LQCTq<b
this.nPos = nPos; 0g\&3EvD
oSavedFile.seek(nPos); .EQFHStr
} ln7.>.F
Fjb[Ev
d-aF-
public synchronized int write(byte[] b,int nStart,int nLen) mH"`46
{ Q<qIlNE
int n = -1; @hPbD?)M
try{ Ja1*a,],L
oSavedFile.write(b,nStart,nLen); mHy]$Z
n = nLen; 2BY:qz%:
} lhU#/}Z
catch(IOException e) &D#v0!e~x
{ X(9Ff=0.~
e.printStackTrace (); KNhH4K2iP8
} DGnswN%n1
lLv0lf
xB#E&}Ho
return n; cAS5&T<
} HS7!O
EC0auB7G
r{_'2Z_i
} <[bDNe["?
I\_R& v
;z#9>99rH
/* YX(%jcj*
**SiteInfoBean.java ~S9nLb:O{
*/ C Qebb:y
package NetFox; |%}?*|-
4=Zlsp
(Lp-3Xx
public class SiteInfoBean { JQqDUd
%oo&M;
{T9g\F*
private String sSiteURL; //Site's URL kMA>)\
private String sFilePath; //Saved File's Path U Lq%,ca
private String sFileName; //Saved File's Name RfD$@q9
private int nSplitter; //Count of Splited Downloading File Y~6pJNR
gE&f}M-
E:ytdaiT
public SiteInfoBean() `}bUf epMJ
{//nSplitter的缺省值为5 ?l/rg6mbI'
//default value of nSplitter is 5 x?kZD~|{)
this("","","",5); uH#NJoRO
} ZI1RB fR
h;6@-\6
ntT|G0E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q.Acmht#
{ T-\,r
sSiteURL= sURL; gM8eO-d
sFilePath = sPath; c8u0\X,
sFileName = sName; >,v~,<3 i
this.nSplitter = nSpiltter; 1NTe@r!y
U7W ct %
6!$S1z#wM
} C{D2mSS
4}CRM# W2
.&ZVy{uP
public String getSSiteURL() {:Q2Itsy
{ |Yx8Ez
return sSiteURL; :1iw_GhJf
} @P-7a`3*
A28w/=e7
3O.-'U1K
public void setSSiteURL(String value) khR3[ju{^
{ I'gnw~
sSiteURL = value; "~ /3
} \yqiv"'
;Cwn1N9S
gOkO8P6P8
public String getSFilePath() WXM_H0K
{ #df43_u
return sFilePath; \=@}(<4
} QqDF_
Wi[Y@
ru&RL HFV
public void setSFilePath(String value) !"kvXxp^
{ Fri5_rxLl
sFilePath = value; lbPxZ'YO#
} TcC=_je460
9#p^Z)[)-
_FV.}%W<u
public String getSFileName() Rm RV8 WJ6
{ ;ry{cq
return sFileName; H|^4e
} +SJ aE] $
%[0"[<1a
#yqcUbJY0R
public void setSFileName(String value) bY<"$);s
{ jC oZm(bi
sFileName = value; M;E&@[5
} I9MI}0}7
%nIjRmqM~
t!k 0n&P
public int getNSplitter() 9we=aX5
{ rEViw?^KT
return nSplitter; S.I<Hs
} <[q)2 5RL
A-~)7-
gp}S1
public void setNSplitter(int nCount) oH;Y}h
{ #\jPBLc
nSplitter = nCount; H0Tt(:.&
} T&c[m!}X|t
} 7+c@pEU]
r'8e"pTi
4e:hKv,+4
/* Wj3H y4
**Utility.java A;g[G>J
*/ pSAXp#g
package NetFox; B<)(7GTv7"
8dpVB#]pp,
-&&mkK B!
public class Utility { P)H%dJ^l
TQ BL!w
WlY%f}ln
public Utility() lRrOoON
{ V6!oe^a7'
;R67a V,
^,X+ n5q;m
} >ko;CQR
/i]Gg \)
//线程睡眠 eI[z%j[Y*
public static void sleep(int nSecond) NZ_45/(dx
{ 4M:oa#gh@
try{ a}fW3+>
Thread.sleep(nSecond); <sTaXaq?
} T4UY%E!0
catch(Exception e) Y}Ov`ZM!r
{ &8(2U-
e.printStackTrace (); G0^PnE0-
} f ZISwr
} _E~uuFMn*R
OS!47Z /q
//日志 ]/a?:24[
public static void log(String sMsg) ^cY5!W.q8
{ c(~M<nL0
System.err.println(sMsg); 5E%W;$3Pb
} HiWZ?G
:\>UZ9h #
o;O_N^_W
public static void log(int sMsg) B<oi,S
{ Ywni2-)<
System.err.println(sMsg); 3w-0v"j U
} mF_/Rhu
} $q+7,,"
snK/,lm.
[Nq4<NK
/* H95VU"
**TestMethod.java hIdGQKr>V
*/ 9KP+
package NetFox; x&f?c=\F
>1r>cZn
7#RW4ZM
public class TestMethod { Ghj6&K%b0
,^'Y7"
KLxg
public TestMethod() wCdUYgsPT"
{ ///xx/weblogic60b2_win.exe ubgq8@;
try{ "XH]B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hP|5q&wX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?GFVV->i
SiteFileFetch fileFetch = new SiteFileFetch(bean); -wO`o<
fileFetch.start(); #><.zZ
} Ao,lEjNI
catch(Exception e){e.printStackTrace ();} {!,+C0
='mqfGRi>
k'{lo_
} u-?&~WA
a E#s#Kv
=e4,)Wd9&
public static void main(String[] args) ve>8vw2
{ Ar\`OhR
new TestMethod(); #3qkG)
} {u!,TDt*
} g'IS8@
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