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)); 1]A$
} !*1$j7`tP
for(int i=0;i<nEndPos.length-1;i++) .C*mDi)wZ
{ %;eD.If}
nEndPos = nStartPos[i+1]; -^aJ}[uaI
} [o"<DP6w
nEndPos[nEndPos.length-1] = nFileLength; 9$?Sts}6&
} D 0 O^=v|
} )UCc!
Iz^vt#b
#soV'SFG
//启动子线程 bQ3txuha
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [} zzG@g,J
for(int i=0;i<nStartPos.length;i++) kz\Ss|jl
{ 7 'q *(v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ve]hE}o/}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dfP4SJqq
nStartPos,nEndPos,i); @9tzk [
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <I#nwoHN
fileSplitterFetch.start(); sg8[TFX@Z
} hm*cGYV/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *\(MG|S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rez)$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V1&qgAy~
nEndPos = " + nFileLength); L</k+a?H!
// fileSplitterFetch[nPos.length-1].start(); hYht8?6}m
{vq| 0t\-
8c\\-{
//等待子线程结束 M ui\E
//int count = 0; O joa3
//是否结束while循环 )_YB8jUR-X
boolean breakWhile = false; o(k{Ed
M$48}q+
ZZn$N-
while(!bStop) 7 x'2
{ uOO\!Hqq
write_nPos(); ysj5/wtO0
Utility.sleep(500); apOa E7|
breakWhile = true; Q+oV? S3{
3=Q:{
=%B5TBG
for(int i=0;i<nStartPos.length;i++) 5-hnk' ~
{ Z)}UCi+/".
if(!fileSplitterFetch.bDownOver) r7,}"Pl
{ e\em;GTy
breakWhile = false; B<Q)z5KK
break; 0NeIQr1N_
} *`q?`#1&&.
} : eCeJ~&E
if(breakWhile) Sv_Nb>
break; 0|Xz-Y
=C2KHNc
vc :%
//count++; /&c2O X|Z
//if(count>4) g#MLA5%=u
// siteStop(); o1vK2V
} 5Xf]j=_
;I&XG
j4<K0-?
System.err.println("文件下载结束！"); Xhq7)/jp
} NS65F7<&
catch(Exception e){e.printStackTrace ();} P(3k1SM
} [#9i@40
WfD fj
EV?U !O
//获得文件长度 T](}jQxj`
public long getFileSize() RG*Vdom
{ \BuyJskE
int nFileLength = -1; ^)wKS]BQ..
try{ zak|* _
URL url = new URL(siteInfoBean.getSSiteURL()); a'-u(Bw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d:kn%L6k_
httpConnection.setRequestProperty("User-Agent","NetFox"); Wqkzj^;"G
lYTQg~aPm
X$;&Mdo.
int responseCode=httpConnection.getResponseCode(); |his8\C+x
if(responseCode>=400) B>W8pZu-J
{ 0-uw3U<
processErrorCode(responseCode); XZ . T%g
return -2; //-2 represent access is error _6Y+E"@zs
} lXg5UrW
P}]o$nWT
ESNI$[`
String sHeader; @ 5^nrB
-OSj<m<
^DN:.qQ
for(int i=1;;i++) 8L,=Eap
{ FieDESsX>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >MGWN
//Utility.log(in.readLine()); c}+*$DeT
sHeader=httpConnection.getHeaderFieldKey(i); u4_QLf@I
if(sHeader!=null) 3 3|t5Ia
{ {"+M%%`*#
if(sHeader.equals("Content-Length")) PJcfiRa'jQ
{ s-_D,$ |
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =#/Kg_RKL
break; m`9nDiV
} J*[@M*R;&
} f-G)pHm
else R0}1:1}$Sn
break; 59O-"Sc[
} s(nT7x+W
} b,^Gj]7
catch(IOException e){e.printStackTrace ();} J09jBQ]R
catch(Exception e){e.printStackTrace ();} kDE-GX"Y
~\mh\a&
i1|>JM[V
Utility.log(nFileLength); +4.s4&f)
#D4
{BmqUoZrC
return nFileLength; G.H8 ><%
} T#H^ }`
!uQT4<g
^3TNj
//保存下载信息（文件指针位置） N(Ru/9!y"
private void write_nPos() ejlns ~
{ |82q|@e
try{ 1!KROes4
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~PI2G9
output.writeInt(nStartPos.length); E?G'F3i
for(int i=0;i<nStartPos.length;i++) J7* o%W*V
{ X58U>4a
// output.writeLong(nPos); 4%^z=%
output.writeLong(fileSplitterFetch.nStartPos); {_Wrs.a'8
output.writeLong(fileSplitterFetch.nEndPos); 755,=U8'wi
} n&njSj/
output.close(); W48RZghmx
} RkE)2q[5
catch(IOException e){e.printStackTrace ();} Ln4]uqMG.
catch(Exception e){e.printStackTrace ();} Z^:_,aJ?
} `UTPX'Vz
d/bimQ
${MzOi
//读取保存的下载信息（文件指针位置） x-m*p^}
private void read_nPos() T@tsM|pI
{ (T_-`N|
try{ hO]F\0+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3uocAmY
int nCount = input.readInt(); z.Ic?Wz7
nStartPos = new long[nCount]; bGCC?}\
nEndPos = new long[nCount]; ==OUd6e}
for(int i=0;i<nStartPos.length;i++) /)6T>/
{ &t^*0/~
nStartPos = input.readLong(); -67Z!N
nEndPos = input.readLong(); UDh\%?j
} (N}-]%#
input.close(); ~;3yjO)l?)
} !?nO0Ao-$
catch(IOException e){e.printStackTrace ();} KClkPL!jP
catch(Exception e){e.printStackTrace ();} y#j7vO
} 4<i#TCGex3
XI\Slq
Jh3
private void processErrorCode(int nErrorCode) P |tyyjO
{ >$JE!.p%o
System.err.println("Error Code : " + nErrorCode); C< c6Ub
} y>EW,%leC
|%C2 cx
XM`GK>*aC(
//停止文件下载 ?$|tT\SFV
public void siteStop() !0W(f.A{K
{ `NNP<z+\
bStop = true; 8Yh'/,o=L#
for(int i=0;i<nStartPos.length;i++) [)Nt;|U
fileSplitterFetch.splitterStop(); J<0{3pZY
9wYm(7M6
~_fc=^o
} wa8jr5/k"
} a9-Mc5^'n
//负责部分文件的抓取 N1Vj;-
**FileSplitterFetch.java A0<g8pv
*/ $@L;j
package NetFox; k|/VNV( =0
Wx:v~/r
I=kqkuW
import java.io.*; 2Mt$Dah
import java.net.*; ,Z~`aHhr
!T,<p
|*NLWN.ja)
public class FileSplitterFetch extends Thread { |dgiW"tUm
~JT`q:l-q
] 0X|_bU
String sURL; //File URL wH ,PA:
long nStartPos; //File Snippet Start Position G}8tFo.d1
long nEndPos; //File Snippet End Position <D.E.^Y
int nThreadID; //Thread's ID C}h(WOcr`X
boolean bDownOver = false; //Downing is over ` IVQ
boolean bStop = false; //Stop identical z}[u~P,
FileAccessI fileAccessI = null; //File Access interface AkQ(V
R!M'
rWTaCU^qV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "du(BZw
{ m^QoB
this.sURL = sURL; ^*}D*=>\
this.nStartPos = nStart; 7Mh'x:p
this.nEndPos = nEnd; 28"1ONs3
nThreadID = id; j2D!=PK;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f6Y?),`
} sE?%;uBb
|HycBTN#E
OkciL]
public void run() A;;#]]48
{ @} r*KF-
while(nStartPos < nEndPos && !bStop) PaaMh[OmG
{ Z?+ )ox
}dN\bb{#
tx5bmF;b)
try{ ".>#Qp%
URL url = new URL(sURL); BQ6$T&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u&l;\w
httpConnection.setRequestProperty("User-Agent","NetFox"); `,V&@}&"n
String sProperty = "bytes="+nStartPos+"-"; 6>WkisxG
httpConnection.setRequestProperty("RANGE",sProperty); jWUrw
Utility.log(sProperty); 9K&$8aD
:zU4K=kR
~!({Unt+'
InputStream input = httpConnection.getInputStream(); k9 r49lb
//logResponseHead(httpConnection); c +]r
I0F[Z\U
t\/H.Hb
byte[] b = new byte[1024]; E<yQB39
int nRead; (d&" @
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1'hpg>U
{ wo&IVy@s$
nStartPos += fileAccessI.write(b,0,nRead); 5$U49j
//if(nThreadID == 1) 0aY|:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :$G^TD/n
} &E]) sJ0
;-1KPDIp`
JYc:@\
Utility.log("Thread " + nThreadID + " is over!"); s]m]b#1!r
bDownOver = true; 12 )
//nPos = fileAccessI.write (b,0,nRead); rPB Ju0D"
} q?j7bp]
catch(Exception e){e.printStackTrace ();} e)HFI|>
} wf ]Wm
} E/H9#
0")_%
C/!P&`<6
//打印回应的头信息 Zg_b(ks
public void logResponseHead(HttpURLConnection con) \l=A2i7TQ
{ ikZYc ${
for(int i=1;;i++) }!K #
{ gX!K%qJBg
String header=con.getHeaderFieldKey(i); bmHj)^v5]
if(header!=null) A5R"|<UPR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `m'RvUc
Utility.log(header+" : "+con.getHeaderField(header)); mCnl@
else .B^tEBGVD
break; ]4O!q}@Cd
} 3SY1>}(Y
} y0 vo-Q
|~76dxU
I_B%F#X)
public void splitterStop() @u+LF]MY
{ z/j*zU `
bStop = true; /*g0M2+OZo
} `V/kM0A5
x<t?Yc9
7 :\J2$P
} pp|$y\ZzB
6U).vg<
MZ)lNU l
/* RQ8"vF#
**FileAccess.java x6aVNH=
*//文件访问(定位，写) Mprn7=I{Tg
package NetFox; GfgHFv
import java.io.*; &x (D%+
rE"FN~9P
<DMm [V{
public class FileAccessI implements Serializable{ ]Y,V)41gCE
0]ai*\,W7~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 sfVzVS[
RandomAccessFile oSavedFile; `_&vvJPn@!
long nPos; 1&h\\&ic
nVpDjUpN
wI7.M Gt
public FileAccessI() throws IOException yTc&C)Jba
{ Z2;~{$&M+
this("",0); FS7D
} >uJu!+#
3Q&@l49q
z>W?\[E<2
public FileAccessI(String sName,long nPos) throws IOException WG3_(mM
{ f/ 3'lPK^
oSavedFile = new RandomAccessFile(sName,"rw"); .mnkV -m
this.nPos = nPos; 2kgSIvk\
oSavedFile.seek(nPos); -4Q\FLC'k
} fda2dY;
YPs9Pqkn
:S`12*_g"
public synchronized int write(byte[] b,int nStart,int nLen) {_>XsB
{ p>U= Jg
int n = -1; T2?.o.&u
try{ G~zfPBN0D
oSavedFile.write(b,nStart,nLen); _+}o/449
n = nLen; 2(Xu?W 7d
} !FK)iQy$0
catch(IOException e) (Rs;+S
{ &/Gf@[
e.printStackTrace (); 9r:|u:i7m
} 3W[||V[r]<
\0*dKgN
_+Z;pt$C
return n; HH3Z?g
} f4`Nws-dP
4<EC50@.
Ga^:y=m
} "6~+-_:
A{3nz DLI
K6F05h 5S
/* t[HsqnP
**SiteInfoBean.java pgUjje>#
*/ cr18`xU
package NetFox; IUWJi\,
PE_JO(e;Xm
n-?zH:]GG{
public class SiteInfoBean { ZP:+'\&J
uxX 3wY;M
\R 3O39[
private String sSiteURL; //Site's URL >kuu\
private String sFilePath; //Saved File's Path iYW<qgz
private String sFileName; //Saved File's Name `/G9*tIR8g
private int nSplitter; //Count of Splited Downloading File -lfbn=3
{rF9[S"h
}_}LaEYAo
public SiteInfoBean() c?Zi/7
{//nSplitter的缺省值为5 DEPsud;
//default value of nSplitter is 5 (nkiuCO
this("","","",5); N7q6pBA"E
} oB<!U%BN
qus%?B{b}
ubKp P%Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'v(b^x<ZS
{ wgQx.8 h>
sSiteURL= sURL; :VR%I;g;
sFilePath = sPath; =FAIbM>u
sFileName = sName; Yru,YA
this.nSplitter = nSpiltter; *aYuuRx
6ZXRb
#/t+h#jG
} {XXnMO4uR;
;t/KF"
$F/xv&t
public String getSSiteURL() .8|"@
{ qP9`p4c8i
return sSiteURL; b$/7rVH!
} 7$Cv=8
R_80J=%0
s?9`dv}P
public void setSSiteURL(String value) Tkj F/zv
{ /mn'9=ks
sSiteURL = value; p8iKZI]g
} *y~~~ 'J/
e\ZV^h}TQ
H@|m^1
public String getSFilePath() U*BI/wZ
{ $GD Q1&Z
return sFilePath; u`*1OqU
} 0\1g-kc!v
%mS>v|
iML?`%/vN
public void setSFilePath(String value) 'kJyE9*xU.
{ K7,Sr1O `
sFilePath = value; I#(?xHx
} K:$GmV9o
3my_Gp
0.~s>xXp
public String getSFileName() E,/nK
{ QwnqysNx4
return sFileName; U_wIx
} S;u2B_/
-;YhQxxC}L
h\6 t\_^\
public void setSFileName(String value) 0<Rq
{ [mo9?
sFileName = value; #,SPV&
} Jn\>Sz(96
N8*QAekN
1/=6s5vS}
public int getNSplitter() e=ry_@7
{ 0J.]`kR
return nSplitter; |-]'~@~
} k4JTc2b
fTGVG
.p78 \T
public void setNSplitter(int nCount) Hr(%y&0
{ ,H]S-uK~
nSplitter = nCount; ;(Z9.
} O}z-g&e.U
} p-6T,')
G[zVGqk
G4EuW *~
/* e'3y^Vg
**Utility.java K{iC'^wP
*/ %\1W0%w
package NetFox; Y";KWA}b
!!)NER-dv
=BO>Bi&&
public class Utility { C:vVFU|4
|cl*wFm|3
/b."d\
public Utility() 3oPyh $*
{ 5?>ES*
>UXNR`?
`>HrO}x^
} kq>I?wg
L1MG("R
//线程睡眠 =<r1sqf
public static void sleep(int nSecond) XJA];9^
{ Z1U@xQj
try{ I(qFIV+HR
Thread.sleep(nSecond); CE|rn8MB
} Lr*\LP6jx3
catch(Exception e) [$`%ve
{ }k@SmO8
e.printStackTrace (); mv#*%St5
} tPFj[Y~Iy
} O0sLcuT$
vSwRj<|CF
//日志 (~?p`g+I.P
public static void log(String sMsg) [`!%u3
{ n"Wlfd0
System.err.println(sMsg); *~`BG5w
} Ed1y%mR>
CWSc#E
UYhxgPGsj
public static void log(int sMsg) ZDmY${J
{ ^]?juL
System.err.println(sMsg); R|]n;*y
} {vp*m:K
} [G"Va_A8
5Rae?*XH
yVyh\u\
/* pL,l
**TestMethod.java yKC1h`2
*/ 1H8/bD
package NetFox; Q6xA@"GJ
[$z-
)h0b}HMW)
public class TestMethod { +77B656
C40o_1g
c6VyF=2q
public TestMethod() )D&xyC}
{ ///xx/weblogic60b2_win.exe |u+!CR
try{ HbJ^L:/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OU<v9`<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H`rd bE
SiteFileFetch fileFetch = new SiteFileFetch(bean); (btmg<WT"
fileFetch.start(); H4<Q}([w
} V+t's*9o3
catch(Exception e){e.printStackTrace ();} l\ VrD2j8
$t0JfDd6Ky
_7'5IA
} upGLZ#
_IWLC{%V
xcH&B%;f
public static void main(String[] args) #tA/)Jvi
{ @I#uv|=N
new TestMethod(); P+DIo7VTX
} dj{~!}
} 0!M'z
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