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)); ]w z`j1
} h`n,:Y^++P
for(int i=0;i<nEndPos.length-1;i++) >+y[HTf-
{ rZ`ob x\S
nEndPos = nStartPos[i+1]; 9r.Os
} *TQXE:vZ[
nEndPos[nEndPos.length-1] = nFileLength; umZy=KHj
} ZGgKCCt
} Rd~-.&
9TRS#iVL+*
%suSZw`
//启动子线程 6L[Yn?;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u;p.:{'
for(int i=0;i<nStartPos.length;i++) o))z8n?b
{ 734)s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d_s=5+Yj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L+,p#w
nStartPos,nEndPos,i); %+gYZv-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =Hplg>h)
fileSplitterFetch.start(); AsJN~<0h
} I3`WY-uv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5%,5Xe4p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E~vM$$O$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3V~871:-~
nEndPos = " + nFileLength); wSoIU,I
// fileSplitterFetch[nPos.length-1].start(); o1C1F}gxU
QND{3Q
Cw7 07
//等待子线程结束 h[~JCYA
//int count = 0; +(n&>75
//是否结束while循环 ?O3E.!Q|
boolean breakWhile = false; V45A>#?U
87WIDr
..BIoSrj
while(!bStop) uYVlF@]
{ CT5\8C
write_nPos(); l~P%mVC3m
Utility.sleep(500); T-e'r
breakWhile = true; 7\x7ySM
ZlQ@k{Es~
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for(int i=0;i<nStartPos.length;i++) Tbf't^Ot$
{ 3!E*h0$}
if(!fileSplitterFetch.bDownOver) ZL/iX~}a'
{ {8+FxmH
breakWhile = false; -]yM<dP
break; 8R?X$=$]!.
} "Bl]_YPv
} ;e,_F/@`
if(breakWhile) q.sErr[zc
break; to9~l"n.s
!p$HS0c
P^9y0Q
//count++; }-YM>q
//if(count>4) JSz;>
// siteStop(); pG"pvfEl9f
} yOR]r+8
b(^/WCykH
W^j;"qj
System.err.println("文件下载结束！"); ED0\k $
} 2ZTz{|y
catch(Exception e){e.printStackTrace ();} Bgb~Tz'
} KnL-qc
MLD1%* &0
@bs YJ4-V
//获得文件长度 @yc/1u$r
public long getFileSize() qe. Qjq
{ 2to~=/.
int nFileLength = -1; |2RoDW
try{ [+,%T;d;
URL url = new URL(siteInfoBean.getSSiteURL()); : :;YS9e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aumWU{j=
httpConnection.setRequestProperty("User-Agent","NetFox"); *}fs@"S
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int responseCode=httpConnection.getResponseCode(); ',Y`XP"Q
if(responseCode>=400) 'T=$Q%Qv
{ VF#2I%R*
processErrorCode(responseCode); ])`+ 78
return -2; //-2 represent access is error x=-dv8N?
} =NJ:%kvF
=VA5!-6<Uq
rl:6N*kK
String sHeader; X}jWNN
]QM{aSvXA
i'XW)n
for(int i=1;;i++) N RB>X
{ _8zZ.~)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T}fH
//Utility.log(in.readLine()); [l~Gwaul>
sHeader=httpConnection.getHeaderFieldKey(i); ;MSdTHN"
if(sHeader!=null) 72Zp%a=
{ VtM:~|v
if(sHeader.equals("Content-Length")) )|52B;yZx
{ 87&BF)]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); YdgDMd-1
break; W=QT-4
} S ^5EG;[
} {T;A50
else [\i0@
break; S"-q*!AhK
} 6f=,$:S$
} ~HW8mly'
catch(IOException e){e.printStackTrace ();} .kbo]P
catch(Exception e){e.printStackTrace ();} Z\1*g k
,[gu7z^|
%IAZU c
Utility.log(nFileLength); k[_)5@2
vI84=n
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return nFileLength; 7E0L-E=.
} A(Tqf.,G
i^<P@ |q
K;ncviGu
//保存下载信息（文件指针位置） ?WVp,vP
private void write_nPos() LUPh!)8
{ v3zd>fDnRp
try{ Z~X\Z.
output = new DataOutputStream(new FileOutputStream(tmpFile)); fRcs@yZnS
output.writeInt(nStartPos.length); f&=WgITa
for(int i=0;i<nStartPos.length;i++) FCr^D$_w
{ -_%8Q#"
// output.writeLong(nPos); v@xbur\L
output.writeLong(fileSplitterFetch.nStartPos); `Zdeq.R]
output.writeLong(fileSplitterFetch.nEndPos); 2YW|/o4
} Re[x$rw
output.close(); 3bWYRW
} B|fh 4FNy
catch(IOException e){e.printStackTrace ();} /5**2Kgv1
catch(Exception e){e.printStackTrace ();} J&hzr t
} yW=I*f
Q4;%[7LU
T O]wD^`
//读取保存的下载信息（文件指针位置） OV~]-5gau
private void read_nPos() tVUC@M>'
{ 0c-.h
try{ \`kH2`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h)NZG6R
int nCount = input.readInt(); BB$(0mM^
nStartPos = new long[nCount]; 7O.?I# 76
nEndPos = new long[nCount]; t[r<&1[&
for(int i=0;i<nStartPos.length;i++) ^X?D4a|;#g
{ uT Z#85L`
nStartPos = input.readLong(); c6f=r
nEndPos = input.readLong(); ^i"~6QYE
} tfAO#htq
input.close(); LMGo8%2I
} R>C^duos.
catch(IOException e){e.printStackTrace ();} <2.87:
catch(Exception e){e.printStackTrace ();} sxK|0i}6
} tyI!y~-z
KfPYH\0
`F(ghC
private void processErrorCode(int nErrorCode) tz^2?wO
{ Rfx}[!<{N
System.err.println("Error Code : " + nErrorCode); Y^Y1re+}
} w'r?)WW$
av8\?xmo.$
^ ,cwm:B@
//停止文件下载 RV=Z$
public void siteStop() .="/n8B
{ V7gv@<1<y
bStop = true; &s{" Vc9]
for(int i=0;i<nStartPos.length;i++) |T;]%<O3E
fileSplitterFetch.splitterStop(); Au\j6mB
Lu][0+-
swTur
} RV_(T+
} %U uVD
//负责部分文件的抓取 _\ &N<
**FileSplitterFetch.java .%"s| D
*/ ahUc;S:v#
package NetFox; }x~1w:zHd
Lw1aG;5
/cXVJ(#j
import java.io.*; {CaTu5\
import java.net.*; au;ZAXM|
(DnrJ.QU}t
VpO+52&
public class FileSplitterFetch extends Thread { \RF{ITV$kD
xb (Cd
sX c|++
String sURL; //File URL h>:eu#
long nStartPos; //File Snippet Start Position +7V4mF!u
long nEndPos; //File Snippet End Position }o:sU^Pwa
int nThreadID; //Thread's ID >qL-a*w:a
boolean bDownOver = false; //Downing is over |y%M";MI
boolean bStop = false; //Stop identical [-p?gyl
FileAccessI fileAccessI = null; //File Access interface Z(|'zAb^
3 q^^Os
X+%5q =N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s[n*fV']A
{ K\VL[HP-
this.sURL = sURL; wfMtWXd;KB
this.nStartPos = nStart; ]n 'FD|
this.nEndPos = nEnd; L5RBe
nThreadID = id; #wS/QrRE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uLq%Nu
} +?%LX4Y
[h0.k"&[
YVW`|'7)|
public void run() &a9Y4~e::
{ 3*C|"|lJ
while(nStartPos < nEndPos && !bStop) 5faY{;8
{ Tya[6b!8
XIRvIwO
^V?W'~
try{ 0K:3?Ik
URL url = new URL(sURL); "/g\?Nce
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DlF6tcoI
httpConnection.setRequestProperty("User-Agent","NetFox"); 5<77o|
String sProperty = "bytes="+nStartPos+"-"; KM9)
httpConnection.setRequestProperty("RANGE",sProperty); $gPR3*0
Utility.log(sProperty); 9NEL[J|
40m>~I^q}
2_C&p6VGj
InputStream input = httpConnection.getInputStream(); A>B_~=
//logResponseHead(httpConnection); Ap)pOD7
=}1m.
lBZhg~{
byte[] b = new byte[1024]; %4I13|<A`
int nRead; u}(K3H3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +6;1.5Tc
{ 3q)y;T\yW
nStartPos += fileAccessI.write(b,0,nRead); SLjSNuOP
//if(nThreadID == 1) py%_XL=w,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5tUN'KEbN
} ,xOOR
2od9Q=v~
caD|*.b
Utility.log("Thread " + nThreadID + " is over!"); ~ \3j{pr
bDownOver = true; +2 x|j>
//nPos = fileAccessI.write (b,0,nRead); 5~H}%W,P
} ;-"'sEu}
catch(Exception e){e.printStackTrace ();} %^LwLyoVM
} w(cl,W/w
} cz.,QIt_
=g^k$ Rc
\Pt_5.bTs[
//打印回应的头信息 $/|2d4O:{
public void logResponseHead(HttpURLConnection con) >`)IdX
{ Xo/0lT
for(int i=1;;i++) 'FC#O%l
{ }~+_|
String header=con.getHeaderFieldKey(i); 7T/hmVi_
if(header!=null) +2Wijrn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H^JwaF
Utility.log(header+" : "+con.getHeaderField(header)); -;RW)n^n
else z$b'y;k
break; )Q)H!yin
} yN:U"]glC
} *$*V#,V-
.3:s4=(f
"3e1 7dsY
public void splitterStop() Sc,ajT
{ .H7xG'$
bStop = true; Y8@TY?
} $e/[!3CASP
%WO4uOi:@
5$<Ozkj(
} a8v9j3.
Jknit
vI5'npM
/* OqlP_^Zz7p
**FileAccess.java !v?WyGbUg
*//文件访问(定位，写) r~Vb*~U"
package NetFox; +xojnv
import java.io.*; /~}<[6ZGCY
tJ9-8ZT*
3.@I\p}
public class FileAccessI implements Serializable{ ZO\x|E!b
@*"H{xo.U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ! ~3zp L
RandomAccessFile oSavedFile; &p83X
long nPos; %Z!3[.%F
XyrQJ}WR|
6< @F
public FileAccessI() throws IOException MwO`DrV
{ zwJK|Sk
this("",0); NsUP0B}.
} Uk<2XGj
fiZq C?(
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public FileAccessI(String sName,long nPos) throws IOException (\*+HZ`(Uu
{ hVf;{p &
oSavedFile = new RandomAccessFile(sName,"rw"); P`]p&:
this.nPos = nPos; q-R'5p\C?|
oSavedFile.seek(nPos); (^9dp[2
} 2x<4&^
0o_wy1O1,
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public synchronized int write(byte[] b,int nStart,int nLen) O]%Vh l
{ j5~nLo2
int n = -1; apw/nhQ.[
try{ |]+PDc%
oSavedFile.write(b,nStart,nLen); ^J?y mo$>0
n = nLen; D'Y=}I)8Dn
} xG~7kj3
catch(IOException e) &p_V<\(%
{ Ew>lk9La(
e.printStackTrace (); $4u8"ne)
} }&Kl)2:O
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return n; SU>cJ*
} _8ubo\M~
/& wA$h
/@feY?glc
} D+('1E?
c!Wj^
rLx'.:
/* KGNBzy~9
**SiteInfoBean.java T%[!m5
*/ Z<W`5sop^
package NetFox; o*Kl`3=]
XO,gEn&6V
tA{?-5
public class SiteInfoBean { xXfFi5Eom
zot_ jSV
$Fik]TbQp
private String sSiteURL; //Site's URL ,Uu#41ZOKL
private String sFilePath; //Saved File's Path 6):iu=/i/
private String sFileName; //Saved File's Name k\A[p\
private int nSplitter; //Count of Splited Downloading File M$MFUGS'
SnFAv7_
6y
public SiteInfoBean() 8G?OZ47k#
{//nSplitter的缺省值为5 xn,I<dL39
//default value of nSplitter is 5 jrZH1dvE
this("","","",5); +hUz/G+3
} 2'5u}G9
/Q\|u:oO,
#5=!ew
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H:!pFj
{ 4$MV]ldUI
sSiteURL= sURL; ,@r 0-gL
sFilePath = sPath; 'q, L*
sFileName = sName; !B:wzb_
this.nSplitter = nSpiltter; SeIL
^_!2-QY.~
H-5h-p k
} xF])NZy|
}e0>Uk`[
66Bx,]"6
public String getSSiteURL() 8;Eg>_cL:
{ b2G1@f.U
return sSiteURL; y.+!+4Mg|
} Tv /?-`Y
Xn*>qm
8Y&_X0T|
public void setSSiteURL(String value) se`^g ,]P
{ ve@E.`
sSiteURL = value; Pe)SugCs
} t)^18 z
]D&\|,,(
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public String getSFilePath() L]#b=Y
{ <z R CT
return sFilePath; #[yZP9
} =L&dV]'4P
;$/]6@bqB
mWX{I2
public void setSFilePath(String value) qz&?zzz;
{ #55_hY#
sFilePath = value; hL}AgY@
} z\+Ug9Of
iNv"!'|
*TC#|5
public String getSFileName() 84f^==Y
{ R&FO-{S
return sFileName; `<IaQY
} -mqL[ h,
W~d^ *LZt
l }WvO]
public void setSFileName(String value) !]2`dp\!
{ 9Z lfY1=
sFileName = value; $3yn-'o'A
} eh}I?:(a?
cs7K^D;.V
G}#p4\/
public int getNSplitter() /[,0,B9!3
{ pv@w 8*
return nSplitter; k4`(7Z
} @ *n oma
a&%v^r[
:@K~>^+U
public void setNSplitter(int nCount) 'QQa :3<x
{ WWN2
nSplitter = nCount; $64sf?aZ>#
} ?d`j}
} 8<PQ31
2g$;ZBHO|8
xy+hrbD)j
/* Uj twOv|pF
**Utility.java mG.H=iw
*/ 2*TPW
package NetFox; nZ8jBCh
]7J*(,sp
/A1qTG=Br
public class Utility { cd]def[d
A&L2&ofV&q
Wh^wKF~%
public Utility() X{tfF!+iy
{ rL|9Xru
.9@y*_9
g![?P"i^t
} Hl=M{)q@
p61F@=EL
//线程睡眠 ~As_O6JI
public static void sleep(int nSecond) iG+=whvL
{ ChRCsu~
try{ O~D]C
Thread.sleep(nSecond); *s$:"g-
} 37 d-!
catch(Exception e) + ;_0:+//
{ }E#1Z\)
e.printStackTrace (); xew s~74L
} i9v|*ZM"
} npMPjknl
U[M~O*9
//日志 A O3MlK9t
public static void log(String sMsg) 36\_Y?zx%
{ }T&~DVM
System.err.println(sMsg); z@U5
} UNyk, #4
8]&\FA8
_ pO1XM
public static void log(int sMsg) CSlPrx2\
{ |Pq z0n=v
System.err.println(sMsg); ]:svR@E
} O7z5,-
} z,c=."<z
G!E1N(%o
,$bK)|pGV
/* u+qj_Ej
**TestMethod.java A9o"L.o)
*/ %OJq(}
package NetFox; MQq!<?/
2 sK\.yS
<8BNqbX
public class TestMethod { %:yVjb,Yf
Vu;z|L
J7p?9
public TestMethod() Vw+RRi(
{ ///xx/weblogic60b2_win.exe +k\cmDcb
try{ fF.sT7Az+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +l;AL5h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?<U">8cP
SiteFileFetch fileFetch = new SiteFileFetch(bean); /-&2>4I
fileFetch.start(); ="P&!lu
} 5#Et.P'
catch(Exception e){e.printStackTrace ();} {~EPP .
8SoTABHV
q+W*?a)
} U(5Yg
4q*mEV
5U6b\jxX
public static void main(String[] args) Zqj EVVB
{ /7igPNhx
new TestMethod(); :I8HRkp
} G3j'A{
} VvTi>2(.
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