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)); b~gF,^w
} F'I6aE%
for(int i=0;i<nEndPos.length-1;i++) K="+2]{I
{ ;qMlGXW*q
nEndPos = nStartPos[i+1]; v,0DGR~
} wLbngO=VG
nEndPos[nEndPos.length-1] = nFileLength; i`qh|w/b_
} `2PT 8UM
} >=H8>X
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U&R$(k0zS
//启动子线程 ^=G+]$8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _HsvF[\[
for(int i=0;i<nStartPos.length;i++) sYpogFfV
{ [w f12P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [78 .%b'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %*OJRL`
nStartPos,nEndPos,i); ,)1e+EnV&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1*h7L<#|mQ
fileSplitterFetch.start(); "puz-W'n
} Xdt+\}\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K}BX6dA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w C"%b#(}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S41>VbtEp
nEndPos = " + nFileLength); P{18crC[1
// fileSplitterFetch[nPos.length-1].start(); DF2&j!
Ysu/7o4
5ov%(QI
//等待子线程结束 :(Bi{cw
//int count = 0; ^~l<N@
//是否结束while循环 3;:V1_JA
boolean breakWhile = false; ^q\zC%.
LS'=>s"
U@nwSfp:G
while(!bStop) E6M: ^p*<
{ #9OP.4
write_nPos(); *.g?y6d
Utility.sleep(500); Phu| hx<
breakWhile = true; ISew]R2
VKz<7K\/
c ?XUb[
for(int i=0;i<nStartPos.length;i++) UI C? S
{ M7,MxwZ0k
if(!fileSplitterFetch.bDownOver) 0h4}RmS
{ -QDgr`%5
breakWhile = false; 0(x@ NGb>{
break; o[hP&9>q
} #Ca's'j&f
} N1~$ +
if(breakWhile) ~-wJ#E3g
break; 9'g{<(R]
/g'-*:a
Ws)X5C=A
//count++; ue<<Y"NR
//if(count>4) WG}CPkj
// siteStop(); -oBas4J
} yX3H&F6
Ba|}C(Ws?
i0Q _f!j
System.err.println("文件下载结束！"); Eu.qA9,@U
} @H0%N53nE
catch(Exception e){e.printStackTrace ();} #l#[\6
} MmH_gR
KxmPL
fMPq
//获得文件长度 Q0Qm0B5eY
public long getFileSize() k<zGrq=8J
{ 2Q|*xd4B^
int nFileLength = -1; UMQW#$~C{g
try{ 3}{5 X'
URL url = new URL(siteInfoBean.getSSiteURL()); 5'Jh2r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N('DIi*or
httpConnection.setRequestProperty("User-Agent","NetFox"); ,9wenr
}, &,Dt
<<5 :zlb
int responseCode=httpConnection.getResponseCode(); |!5T+H{Sj
if(responseCode>=400) 9w;J7jgOT!
{ :;q_f+U
processErrorCode(responseCode); .y9rM{h}b
return -2; //-2 represent access is error fhIj+/{_O
} }lUpC}aq_
XqS*;Zj0
Ty0T7D
String sHeader; 8t:&#h
1idjX"'
w<>6>w@GZ
for(int i=1;;i++) OMI!=Upz
{ pkfOM"5'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Po11EZa$a
//Utility.log(in.readLine()); \*!%YTZ~
sHeader=httpConnection.getHeaderFieldKey(i); ^}/ E~Sg7\
if(sHeader!=null) o/ g+Z
{ 6Y_O^f
if(sHeader.equals("Content-Length")) k.xv+^b9Q
{ =>}.W:=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GHC?Tp
break; uj9tr`Zh
} 7M#$: Fdb
} u4,X.3V]A
else b}&7~4zw
break; +}XL>=-5
} ciGpluQF
} tZu*Asx7
catch(IOException e){e.printStackTrace ();} N' $DE
catch(Exception e){e.printStackTrace ();} v7<S F
Prb_/B Dd
h9BD ^j
Utility.log(nFileLength); a;'E}b{`F
x #X#V\w=
A6UdWK
return nFileLength; a}qse5Fr
} M`+e'vdw
k CW!m
_E1]cbIo
//保存下载信息（文件指针位置） Hdbnb[e
private void write_nPos() UK~B[=b9
{ 9p\Hx#^
try{ 7hN6IP*so
output = new DataOutputStream(new FileOutputStream(tmpFile)); Dj ]Hgg
output.writeInt(nStartPos.length); q"LJwV}W
for(int i=0;i<nStartPos.length;i++) y }&4HrT&
{ <% 7P
// output.writeLong(nPos); xngeV_xc2
output.writeLong(fileSplitterFetch.nStartPos); N{V5 D
output.writeLong(fileSplitterFetch.nEndPos); &!DZW5
} F;Q_*0mIQ
output.close(); MX`Wg
} j*H;a ?Y
catch(IOException e){e.printStackTrace ();} \5_P5q:`
catch(Exception e){e.printStackTrace ();} h%1~v$W`
} `gt&Y-
Q3Z%a|3W
H#|Z8^ *Ds
//读取保存的下载信息（文件指针位置） }}``~
private void read_nPos() x?f0Hk+
{ 3Zaq#uA
try{ L* khj3;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8yE%X!E
int nCount = input.readInt(); bQXc IIa{
nStartPos = new long[nCount]; iz9\D*or
nEndPos = new long[nCount]; X"TUe>cM
for(int i=0;i<nStartPos.length;i++) T\2) $
{ M2;%1^
nStartPos = input.readLong(); OK M\"A4
nEndPos = input.readLong(); OAW=Pozr9
} D%;wVnUw
input.close(); (0OSGG9
} J@ktj(
catch(IOException e){e.printStackTrace ();} \'; t*
catch(Exception e){e.printStackTrace ();} pcRF:~TE
} W>}Qer4
e0v9uQ%F5
` $.X[\*U
private void processErrorCode(int nErrorCode) [j:}=:feQ
{ d s|8lz,
System.err.println("Error Code : " + nErrorCode); tp1KP/2w[
} 9Qt)m fqM
2I]]WBW#:
.8T\Nr\~2
//停止文件下载 eW%L$I
public void siteStop() I"8d5a}
{ 6P%<[Z
bStop = true; ilDJwZg#
for(int i=0;i<nStartPos.length;i++) < -Hs<T|tW
fileSplitterFetch.splitterStop(); :b<-[8d&
mD D4_E2*
_l#3]#
} ERp:EZ'
} oF%^QT"R
//负责部分文件的抓取 gB/;clCdX)
**FileSplitterFetch.java }yx=(+jP
*/ /e.FY9
package NetFox; ur/Oc24i1n
H o4B
r+p@X
import java.io.*; d3EjI6R*z
import java.net.*; tSEA999
(@%XWg
"C:rTIH
public class FileSplitterFetch extends Thread { PU^[HC*K
W:VW_3
F3r S6_
String sURL; //File URL 8`:M\*
long nStartPos; //File Snippet Start Position `j"4:
long nEndPos; //File Snippet End Position u{g]gA8s
int nThreadID; //Thread's ID 5*JV )[
boolean bDownOver = false; //Downing is over }x:\69$
boolean bStop = false; //Stop identical 2-8YSHlh
FileAccessI fileAccessI = null; //File Access interface "NxOOLL
pGY [f@_x-
t*o7,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m5e\rMN~>\
{ ?D1x;i9<
this.sURL = sURL; tegOT]|
this.nStartPos = nStart; 8'3"uv
this.nEndPos = nEnd; i Bi7|
nThreadID = id; /t$rX3A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~J%R-{U9
} jZa25Z00
zTkFX67)
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public void run() h^['rmd
{ $TR=3[j
while(nStartPos < nEndPos && !bStop) L5R `w&Up
{ ov1Wr#s
1T!cc%ah
+*n]tlk
try{ "=9-i-K9B
URL url = new URL(sURL); 3b<: :t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cL?\^K)
httpConnection.setRequestProperty("User-Agent","NetFox"); xy2\'kS`G
String sProperty = "bytes="+nStartPos+"-"; h{\t*U54'
httpConnection.setRequestProperty("RANGE",sProperty); DD2adu^
Utility.log(sProperty); )i&%cyZw
,r@xPZPz:e
*:?QB8YJ
InputStream input = httpConnection.getInputStream(); *f{7
//logResponseHead(httpConnection); g+igxC}2z
/d[Mss
>g=^,G}y
byte[] b = new byte[1024]; TKK,Y{{
int nRead; 1d`cTaQ-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z|uOJ0uK
{ ]n~yp5Nbr
nStartPos += fileAccessI.write(b,0,nRead); 4/b(Y4$,[r
//if(nThreadID == 1) 5n:nZ_D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !zU/Hq{wcK
} N A8 sN
_jW>dU^B
9p5= _
Utility.log("Thread " + nThreadID + " is over!"); yGRR8F5>(
bDownOver = true; M/*Bh,M`
//nPos = fileAccessI.write (b,0,nRead); *K`x;r
} iM8sX B
catch(Exception e){e.printStackTrace ();} ^#2xQ5h
} Umij!=GPG^
} nZ~kZ |VS
[@ILc*2O
1^S'sWwe
//打印回应的头信息 Xj%,xm>}!u
public void logResponseHead(HttpURLConnection con) en%J!<&W{K
{ NJk)z&M
for(int i=1;;i++) ^s=*J=k
{ \/n+j!
String header=con.getHeaderFieldKey(i); ~)_K"h.DY
if(header!=null) b(/j\NWC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *u}'}jC1X
Utility.log(header+" : "+con.getHeaderField(header)); f`,-b
else 7"#f!.E
break; u >4ArtF
} GKCM|Y
} +N7"EROc
J||E;=%f-Q
zOL;"/R
public void splitterStop() wE?CvL
{ >:%BNeO
bStop = true; 02(h={
} ZvH?3Jy
0 k9<&
CG.,/]_
} S"Kq^DN
f9a$$nb3`
RtwUb(wn6
/* |U EC
**FileAccess.java "-P/jk
*//文件访问(定位，写) f}2;N
package NetFox; Je 31".
import java.io.*; lY8`5Uz
g>yry}>04%
(vnoP< 0
public class FileAccessI implements Serializable{ &sdx`,
"H$@b`)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ctHEEFWm
RandomAccessFile oSavedFile; |kseKZ3
long nPos; *,&S',S-
9n"V\e_R
Kr]z]4.d@
public FileAccessI() throws IOException 4vLw?_".
{ >L=;"+B0U&
this("",0); modC6d%
} t0.;nv@A0
e}e6r3faz
r%|A$=[Q
public FileAccessI(String sName,long nPos) throws IOException @D]lgq[
{ \E77SO,$
oSavedFile = new RandomAccessFile(sName,"rw"); 0<Q*7aY
this.nPos = nPos; o,*=$/or
oSavedFile.seek(nPos); x6v,lR
} BPewc9RxV
P$OUi!"
xCq'[9oU
public synchronized int write(byte[] b,int nStart,int nLen) tDt :^Bc
{ <h@]Ri
int n = -1; SO_>c+Dw
try{ s4bv;W
oSavedFile.write(b,nStart,nLen); -?z\5z
n = nLen; @$c!/
} @Z q[e
catch(IOException e) G\ex^&M
{ ,56;4)cv
e.printStackTrace (); WqQU@sA
} Ha218Hy0W
MMd.0JuaO
`XgFga)
return n; n}OU Y
} ?-,6<K1
96}eR,
1qZG`Vz
} >pdnCv_c
O:YJ%;w
ZLrHZhP-+
/* GW/WUzK
**SiteInfoBean.java RX>2~^
*/ *)D1!R<\,R
package NetFox; :j,}{)5=
$DE&J4K
" #v%36U
public class SiteInfoBean { PIxjM>
p9iu:MucD<
P)hi||[
private String sSiteURL; //Site's URL esI'"hVJ
private String sFilePath; //Saved File's Path I_>`hTiR
private String sFileName; //Saved File's Name kceyuD$3G
private int nSplitter; //Count of Splited Downloading File y/tSGkMv
#xp(B5
Mk5RHDh
public SiteInfoBean() sLhDO'kM
{//nSplitter的缺省值为5 RRzP*A%=
//default value of nSplitter is 5 W;TJenv
this("","","",5); = F<:}Tx)C
} x7$ax79ly
Hi8Y6|y$D
t!qwxX*$T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y-a|Lu*
{ ^l(^z fsZ
sSiteURL= sURL; ^P$7A]!
sFilePath = sPath; HeozJ^u\?
sFileName = sName; l"\uf(0K
this.nSplitter = nSpiltter; U=m=1FYaG
m&/=&S
Mudrg[@`
} g>n0z5&TNF
A[JM4x
ir&.Z5=
public String getSSiteURL() "DpKrVuG
{ I$j|Rq
return sSiteURL; J-XTN"O
} zy>}L #
ch })ivFP[
>nM%p4E
public void setSSiteURL(String value) UA(;fZ@
{ ]w[ThHRJ
sSiteURL = value; 6fGK(r
} J?D\$u:
rQj~[Y.c
BIfi:7I;Q
public String getSFilePath() 2f..sNz
{ hSMV&Cs
return sFilePath; P%)b+H{$h
} 38Efp$)
X| <yq
fj+O'X
public void setSFilePath(String value) !^v\^Fc
{ WQKj]:qk0
sFilePath = value; OKPJuV`y6
} %rcFT_
jBRPR R0
1X&B:_
public String getSFileName() vGN3 YcH
{ ;J=:IEk
return sFileName; l &Z(K,6
} MZ~.(&
1VLLo~L%
SdI1}&
public void setSFileName(String value) KY+]RxX
{ ipZHSA
sFileName = value; w+_Wc~f
} @a(oB.i
3_zSp.E\l
W4vBf^eC
public int getNSplitter() o](.368+4
{ x)R0F\_
return nSplitter; F$yeF^\g
} . r`[
T2|:nC)@
ML=z<u+
public void setNSplitter(int nCount) 5-w:c>
{ 9h&yuS'Yj
nSplitter = nCount; NvHN -^2
} X9~p4ys9{
} {^m5#f 0"
P(;Mb{
|-61(X.
/* %nQmFIt
**Utility.java %3G;r\|r]
*/ P)1EA;
package NetFox; HNMBXXf,B
6"%2,`Nu
/ O)6iJ
public class Utility { >{XScxaB`
m6MaX}&zv
-*3(a E
public Utility() ]l&'k23~p
{ -tyaE
ke6n/ h5`
X6kaL3L}
} SQ<f
j_c+.iET
//线程睡眠 `M]BhW)
public static void sleep(int nSecond) PL@7KDQ
{ UABbcNW
try{ tJm{I)G
Thread.sleep(nSecond); MYx88y
} 4)nt$fW
catch(Exception e) aAcKwCGq\
{ })7K S?
e.printStackTrace (); /7vE>mSY
} ]]y[t|6
} PbN3;c3
hBy*09Sv
//日志 ,qu:<
public static void log(String sMsg) s41adw>
{ T#r=<YH[C
System.err.println(sMsg); {(0Id!
} +XQPjg
tqhh<u;
'!@A}&]
public static void log(int sMsg) Pz1G<eh#{g
{ mu>] 9ZW
System.err.println(sMsg); UR,?!rJ^B
} }.t^D|
} {*fUJmao"
W5X7FEW
=mLeMk/7 w
/* Xi+n`T'i
**TestMethod.java KBj@V6Q
*/ r0uJ$/!
package NetFox; )f[C[Rd
kQ[Jo%YT?E
WKOI\
public class TestMethod { y($EK(cb
i'iO H|s
t%HI1eO7h
public TestMethod() Y{j7Q4{
{ ///xx/weblogic60b2_win.exe /+29.1#|
try{ m{O Dz:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PJ;.31u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '}CN?f|.
SiteFileFetch fileFetch = new SiteFileFetch(bean); SctJxY(}!
fileFetch.start(); $>![wZ3
} SdSgn|S
catch(Exception e){e.printStackTrace ();} A$ J9U3+O
yWmrdvL
9BO|1{
} ,3k@L\$.x
0}D-KvjyP
4uPH
public static void main(String[] args) H7}g!n?
{ >~^`5a`$uI
new TestMethod(); iel-<(~
} 6N?#b66
} 1y~L8!:L
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