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)); p x1y#Q
} 3/V&PDC*'
for(int i=0;i<nEndPos.length-1;i++) .w3.zZ0[
{ vcs=!Ace
nEndPos = nStartPos[i+1]; R{GOlxKs C
} XB, 2+
nEndPos[nEndPos.length-1] = nFileLength; KB49~7XjQ@
} OcQ>01Q
} f<WP<!N%
aP^,@RrL
i:W.,w%8
//启动子线程 [2I1W1pd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xh"JyDTj3
for(int i=0;i<nStartPos.length;i++) NfizX!w&
{ XB*)d 9'8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3wK{?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }}y$T(:l
nStartPos,nEndPos,i); X@KF}x's
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "Mzb
fileSplitterFetch.start(); c}GmS@
} k4jZu?\C]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WrH7tz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4b]/2H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \U $'3M
nEndPos = " + nFileLength); p2 u*{k{
// fileSplitterFetch[nPos.length-1].start(); 9}4P%>_
! iuDmL
Qa@b-v'by
//等待子线程结束 Iko1%GJ1Z
//int count = 0; U_ n1QU
//是否结束while循环 KdIX`
boolean breakWhile = false; v3!oY t:l
N>##}i
9}^nozR,I
while(!bStop) y}5V3)P
{ |}s)Wo
write_nPos(); eMyh&@7(F
Utility.sleep(500); Vm}OrFA
breakWhile = true; a@:(L"Or
:VpRpj4f
o1<Y#db[
for(int i=0;i<nStartPos.length;i++) 4ti\;55{W
{ X!Ag7^E
if(!fileSplitterFetch.bDownOver) P{j2'gg3
{ g&eIfm
breakWhile = false; i]&C=X
break; !J`>;&
} &nkYJi(!
} Hhx"47:
if(breakWhile) U;QTA8|!&
break; ssaEAm:
x`n$4a'7b
-|;{/ s5
//count++; n{sF'n</
//if(count>4) FG/".dU
// siteStop(); "ee:Z_Sz
} <,!8xp7,~
V4I5PPz~
PyQt8Qlz
System.err.println("文件下载结束！"); {Q9?Q?
} o 4G%m>$
catch(Exception e){e.printStackTrace ();} mQEE?/xX;
} ;e,_F/@`
,z<J`n
@qj4rt"
//获得文件长度 x!5b" "
public long getFileSize() l;{n"F
{ ptJ58U$Bb
int nFileLength = -1; @BQJKPF*
try{ eS(hLXE!7
URL url = new URL(siteInfoBean.getSSiteURL()); >YG1sMV-J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zT$-%
httpConnection.setRequestProperty("User-Agent","NetFox"); &b :u~puM
9N1Uv,OtB
XC44]o4jx
int responseCode=httpConnection.getResponseCode(); =' %r"_`}
if(responseCode>=400) t Qo)*z
{ fny|^F]w
processErrorCode(responseCode); pJ8;7u
return -2; //-2 represent access is error yM* CA,(c
} r~f*aD
Pwc)u&
ivTx6-]
String sHeader; w:[1,rRvT
Qm9r>m6p@N
e!V3/*F
for(int i=1;;i++) a'zXLlXgGd
{ _(A9k{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }ACWSkWK
//Utility.log(in.readLine()); !97U2L4
sHeader=httpConnection.getHeaderFieldKey(i); VtM:~|v
if(sHeader!=null) j&6O1
{ + t%[$"$
if(sHeader.equals("Content-Length")) :Q\Es:y
{ v67utISNI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j%w}hGW%,
break; .kbo]P
} Tt^PiaS!
} %IAZU c
else ;Gf,I1d}{
break; KImBQ2^Tu
} |4E5x9J
} zY11.!2
catch(IOException e){e.printStackTrace ();} *yx5G-#?
catch(Exception e){e.printStackTrace ();} D./!/>@f
i sK_t*
.( )rby
Utility.log(nFileLength); .$o0$`}
Ai*R%#
2YW|/o4
return nFileLength; , ZisJksk
} -'!K("
DJWm7 t
kU75
//保存下载信息（文件指针位置） \r.{Ru
private void write_nPos() CIt%7 \c
{ #1,"^k^
try{ \zx &5a #
output = new DataOutputStream(new FileOutputStream(tmpFile)); / 5\gP//9K
output.writeInt(nStartPos.length); {fd/:B 7T
for(int i=0;i<nStartPos.length;i++) {4C/ZA{|l
{ "r+v^
// output.writeLong(nPos); %pJRu-D
output.writeLong(fileSplitterFetch.nStartPos); R>C^duos.
output.writeLong(fileSplitterFetch.nEndPos); YK{E=<:
} tyI!y~-z
output.close(); $`a>y jma
} >b1#dEY
catch(IOException e){e.printStackTrace ();} a1Kh
catch(Exception e){e.printStackTrace ();} q HU}EEv
} 8\lRP,-
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hx.ln6=4
//读取保存的下载信息（文件指针位置） `GpOS_;
private void read_nPos() On`T pz/
{ 1(YEOZ
try{ hvFXYq_[O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?'8(']/
int nCount = input.readInt(); JmP[9"
nStartPos = new long[nCount]; 7u=R5
nEndPos = new long[nCount]; fOUW{s
for(int i=0;i<nStartPos.length;i++) -qJ%31Mr#
{ :lfUVa{HN
nStartPos = input.readLong(); j@o \d%.'!
nEndPos = input.readLong(); lSG"c+iV
} \jpm
input.close(); _\ &N<
} .%"s| D
catch(IOException e){e.printStackTrace ();} ahUc;S:v#
catch(Exception e){e.printStackTrace ();} v'e5j``=
} 63NhD
wCitQ0?
NZQl#ZJH:
private void processErrorCode(int nErrorCode) 2zPO3xL,
{ Ovhd%qV;Y
System.err.println("Error Code : " + nErrorCode); ]ZI ?U<0
} E9bc pup
v<AFcY
AE@N:a
//停止文件下载 ll^#I/
public void siteStop() 6rll0c~
{ />dH\KvN
bStop = true; u}0U!
for(int i=0;i<nStartPos.length;i++) |y%M";MI
fileSplitterFetch.splitterStop(); [-p?gyl
Z(|'zAb^
IQ]tcSQl
} sy(8-zbI
} !uc"|S?
//负责部分文件的抓取 K\VL[HP-
**FileSplitterFetch.java wfMtWXd;KB
*/ ]n 'FD|
package NetFox; X4$86
1 k\~%
uLq%Nu
import java.io.*; S2\|bs7;J,
import java.net.*; &_o.:SL|
tj1M1s|a
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public class FileSplitterFetch extends Thread { KB5<)[bs
9`FPV`/
t,IQ|B&0
String sURL; //File URL Tya[6b!8
long nStartPos; //File Snippet Start Position XIRvIwO
long nEndPos; //File Snippet End Position mzbMX <
int nThreadID; //Thread's ID K9=f`JI9
boolean bDownOver = false; //Downing is over 17ol %3 M
boolean bStop = false; //Stop identical {x\lK;
FileAccessI fileAccessI = null; //File Access interface '\wZKYVN
hhr!FQ.+/
2JR$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nl/~7({
{ n:P++^ j
this.sURL = sURL; Ap)pOD7
this.nStartPos = nStart; =}1m.
this.nEndPos = nEnd; OaF[t*]D3
nThreadID = id; s;Sv@=\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EHlkt,h*
} W&s@2y?rF
wqE+hKs,
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public void run() ;hZ^zL
{ x*a^msY%
while(nStartPos < nEndPos && !bStop) 7\<}378/^
{ HlgkW&}c^
caD|*.b
~ \3j{pr
try{ nJr:U2d
URL url = new URL(sURL); &<$YR~g5j$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /s[D[:P_
httpConnection.setRequestProperty("User-Agent","NetFox"); 1MYA/l$
String sProperty = "bytes="+nStartPos+"-"; TO]7%aB
httpConnection.setRequestProperty("RANGE",sProperty); 9~|hGo
Utility.log(sProperty); PCX X[N
h7 c
.[:2M9Rx
InputStream input = httpConnection.getInputStream(); bKac?y~S_
//logResponseHead(httpConnection); v[!ZRwk4w3
#Nv)SCc
W</\F&
byte[] b = new byte[1024]; +<$b6^>!$
int nRead; SadffAvSA{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M|9=B<6`7
{ cqZuG}VR
nStartPos += fileAccessI.write(b,0,nRead); <E1ngG
//if(nThreadID == 1) z$b'y;k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )Q)H!yin
} bSm*/Q
yN:U"]glC
4&}dA^F
Utility.log("Thread " + nThreadID + " is over!"); ZB'ms[
bDownOver = true; S*Hv2sl
//nPos = fileAccessI.write (b,0,nRead); KlSg0s
} )2g-{cYv
catch(Exception e){e.printStackTrace ();} R$M>[Kjn
} th]pqhl>
} -,pw[R
g'<ekY+V:
o`%;*tx
//打印回应的头信息 N}X7g0>hV
public void logResponseHead(HttpURLConnection con) %WO4uOi:@
{ #4wia%}u
for(int i=1;;i++) >>R,P Ow-
{ 9 =zZ,dg
String header=con.getHeaderFieldKey(i); ^#p+#_*V
if(header!=null) K<~J*k<v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^/:G`'
Utility.log(header+" : "+con.getHeaderField(header)); x!;;;iS
else $Y=xu2u)
break; 5"^Z7+6
} z8*{i]j
} 4u+4LB*
D\ kd6
2y#[uSqB
public void splitterStop() M0Vs9K=
{ Ns5'K^
bStop = true; SE0&CV4
} JzZ@Z8%a;
{-.ZFUZmT
&!0%"4
} ZK$<"z6{
bPHtP\)
Cy2)M(RW
/* .e1Yd8
**FileAccess.java k^e;V`(
*//文件访问(定位，写) lL6W:Fq@(
package NetFox; Y9ipy_@_?
import java.io.*; bO6LBSZx]
<NlL,
Q%.F Mf
public class FileAccessI implements Serializable{ s%Irh;Bs
344E4F"ph
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~pG,|\9
RandomAccessFile oSavedFile; o@@, }
long nPos; dvPlKLp
P`]p&:
{L.=)zt>
public FileAccessI() throws IOException +A%"_7L}
{ x)OJ?l
this("",0); WwAvR5jq
} ^rssZQKY[
,!Q^"aOT:
j@C*kj;-
public FileAccessI(String sName,long nPos) throws IOException b5t:">wC
{ )L/o|%r!
oSavedFile = new RandomAccessFile(sName,"rw"); o~tL;(sz
this.nPos = nPos; MVXy)9q
oSavedFile.seek(nPos); v|@1W Uc,g
} 29kR7[k
w3Z;&sFd
P{%R*hb]
public synchronized int write(byte[] b,int nStart,int nLen) )9s 6(Iu
{ kcio]@#
int n = -1; ,l7',@6Y
try{ iiD}2yb
oSavedFile.write(b,nStart,nLen); ZxU3)`O
n = nLen; XI7:y4M
} N)Qz:o0W
catch(IOException e) qJq!0F
{ <EM'|IR?
e.printStackTrace (); 2{I+H'w8:
} }KFM8CbS
Z[G:
(MnK \^Y
return n; qfa[KD)!aB
} o7 1f<&1
HsRQiai*
&09g0K66
} !lk9U^wnd
,*j@Zb_r
/6yH ,{(a
/* GjeRp|_Qd<
**SiteInfoBean.java VK3e(7b
*/ Yu_` >so
package NetFox; rO7[{<97m
/\u1q<
8G?OZ47k#
public class SiteInfoBean { xn,I<dL39
jrZH1dvE
+hUz/G+3
private String sSiteURL; //Site's URL 2'5u}G9
private String sFilePath; //Saved File's Path A`ScAzx5{
private String sFileName; //Saved File's Name uG{/yJeU
private int nSplitter; //Count of Splited Downloading File HrH! 'bd
>v1ajI>O&{
idSc#n22
public SiteInfoBean() ;`:A(yN]T
{//nSplitter的缺省值为5 /`VrV{\/!
//default value of nSplitter is 5 KvkU]s_
this("","","",5); |$&v)
} dZ%rmTE(H
OoOr@5g
$0P7^4)w:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,<O|Iis
{ K~Z$NS^W&
sSiteURL= sURL; ;b;Bl:%?
sFilePath = sPath; Zil<*(kv{
sFileName = sName; vd#BT$d?
this.nSplitter = nSpiltter; #Pe|}!)u
I.hy"y2&
B f"L;L
} S7f"\[Aw
ve@E.`
Pe)SugCs
public String getSSiteURL() t)^18 z
{ ]D&\|,,(
return sSiteURL; 1CA%nqlng
} }x(Ewr
1}"Prx-
Bl/Z _@
public void setSSiteURL(String value) #bmbK{[
{ (Qj;B)
sSiteURL = value; 4d;.p1ro
} $i"IOp
h}yfL@
Y:4/06I
public String getSFilePath() /MV2#P@
{ 4'GosQ85
return sFilePath; W'L
} I/Q~rVt
xa$4P [
N%fDgK
public void setSFilePath(String value) I,@ 6w
{ Tjj-8cg
sFilePath = value; O 2W2&vY
} rYPj3!#
0+6=ag%
U_<k*o@:
public String getSFileName() y?ypRCgO.u
{ HA]5:ck
return sFileName; T/iZ"\(~w
} )kvrQ6
_<6B.{$\7m
A!IZIT5)m
public void setSFileName(String value) E5 uk<e_
{ :@K~>^+U
sFileName = value; $_Q]3"U
} a|kEza,]
uQO\vRh0
}Wz[ox9b
public int getNSplitter() =H/ 5
{ @Jc^ur
return nSplitter; -v{LT=,O
} =.2)wA"e'
dr^MW?{a\
y!/:1BHlm
public void setNSplitter(int nCount) yyc4'j+
{ e1Bqd+
nSplitter = nCount; qTI_'q
} |)+45e
} Fr)6<9%xVm
^|ul3_'?
W #V`|JA
/* rL|9Xru
**Utility.java .9@y*_9
*/ g![?P"i^t
package NetFox; Hl=M{)q@
p61F@=EL
@f`s%o
public class Utility { iG+=whvL
H/$oGhvl
s(cC;
public Utility() W ![*0pL
{ ?$~5ti#\
Q&8epO|J
5;X3{$y
} qv)%)n
g [c^7
//线程睡眠 {"mb)zr
public static void sleep(int nSecond) npMPjknl
{ U[M~O*9
try{ A O3MlK9t
Thread.sleep(nSecond); 36\_Y?zx%
} }T&~DVM
catch(Exception e) MTAq}8
{ DTz)qHd#X
e.printStackTrace (); ~=gpn|@b
} g96]>]A<{
} F&$~]R=&
/TY=ig1z
//日志 xbD]EC
public static void log(String sMsg) g]jCR*]
{ j W/*-:
System.err.println(sMsg); A@)ou0[n@
} [ ]42$5eof
UAOH9*9*
h7J4 p
public static void log(int sMsg) U?A3>
{ !+_X q$9_
System.err.println(sMsg); ~RRS{\,
} S#N4!"
} PZk"!I<oN
epG!V#I
lN'b"N
/* 0`Y"xN`'i
**TestMethod.java @o>3 Bv.
*/ #PQhgli
package NetFox; ky I~
RSBk^
zszx~LSvIT
public class TestMethod { h~s h!W8
=O>E>Q
:Hj #1-U
public TestMethod() QSyPtjg]
{ ///xx/weblogic60b2_win.exe +u;RFY^
try{ PH>`//D%n?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4q*mEV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5U6b\jxX
SiteFileFetch fileFetch = new SiteFileFetch(bean); Zqj EVVB
fileFetch.start(); Eg4_kp0Lq
} c|Fu6LF a
catch(Exception e){e.printStackTrace ();} `u$lSGl
Yz? 8n
G-5ezVli
} `Hd~H
$fG~;`T
4nKlW_{,
public static void main(String[] args) o "1X8v
{ Lc_cB`
new TestMethod(); );d"gv(]D
} 4rUOk"li
} ,P^4??' o
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