http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); <(tnClAn
} @g%^H)T
for(int i=0;i<nEndPos.length-1;i++) u;Rm/.
{ ZOzwO6(_
nEndPos = nStartPos[i+1]; / 0ra]}[(
} I4Rd2G_
nEndPos[nEndPos.length-1] = nFileLength; Wagb|B\
} /I~(*X
} $,8}3R5}
J/>9w
"NvB@>S
//启动子线程 G_v^IM#B=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ojbms>a
for(int i=0;i<nStartPos.length;i++) i~ITRi@
{ 7*C>4Gs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W%P$$x5&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t2hI^J0y
nStartPos,nEndPos,i); <d~IdK'\x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fx3X
fileSplitterFetch.start(); 5c 69M5
} YDjjhe+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XFi!=|F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #4Ltw,b^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H$!sK
nEndPos = " + nFileLength); /L; c -^
// fileSplitterFetch[nPos.length-1].start(); 'q7&MM'oS^
hwi$:[
zOn%\
//等待子线程结束 d 6=Z=4w
//int count = 0; <o: O<p@6
//是否结束while循环 Xu%8Q?]
boolean breakWhile = false; a+ s%9l
kn= fW1
2'-o'z<
while(!bStop) RN ~pC
{ ppR;v
write_nPos(); L8~zQV$h
Utility.sleep(500); b@ OF
breakWhile = true; PwS7!dzH-
fp2uk3Bm[
&d@N3y
for(int i=0;i<nStartPos.length;i++) [;$9s=:[
{ ;t\C!A6
if(!fileSplitterFetch.bDownOver) # 5b
{ 6g 5Lf)yG
breakWhile = false; v{O(}@
break; &H:2TL!
} 'M=V{.8U
} r%FfJM@!
if(breakWhile) l5<&pb#b
break; qMmhVUx
tE]Y=x[Ux
.*{0[
//count++; f19'IH$n{
//if(count>4) >*"1`vcxF
// siteStop(); wj-z;YCV
} d6zfP1lQ
@% .;}tC
_KAg1Ww
System.err.println("文件下载结束！"); ftccga
} OYj~"-3y)
catch(Exception e){e.printStackTrace ();} _.+2sm
} Wq"^{
,A;wLI
VL8yL`~zc.
//获得文件长度 3)_(t.$D
public long getFileSize() @ Br?
{ R@lA5w
int nFileLength = -1; 2T3b6
try{ ~vw$Rnotz
URL url = new URL(siteInfoBean.getSSiteURL()); [zr2\(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N(Xg#m
httpConnection.setRequestProperty("User-Agent","NetFox"); kA{eT
E=RX^ 3+}
gi JjE
int responseCode=httpConnection.getResponseCode(); j7 \y1$w
if(responseCode>=400) nrJW.F]S8[
{ EzGO/uZ]
processErrorCode(responseCode); *4O9W8Qz
return -2; //-2 represent access is error j)Y68fKK
} ^wMZG'/
x2Dg92
!f)^z9QX8
String sHeader; wG",Obja
f_;6uCCO
&m{vLw
for(int i=1;;i++) ?xYoCn}Z
{ 8w9?n3z=}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p(pL"
//Utility.log(in.readLine()); 3\H0Nkubts
sHeader=httpConnection.getHeaderFieldKey(i); OHK]=DH:M
if(sHeader!=null) Ry"N_Fb
{ xMD]b
if(sHeader.equals("Content-Length")) yN9setw*,M
{ \><v1x>;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #jT=;G7f2
break; R[f@g;h
} 9 $Ud\
} d5l].%~
else (<ngdf`,
break; ~zyD=jxP9
} k*!f@ M
} ?~WDlj3
catch(IOException e){e.printStackTrace ();} QRlrcauM
catch(Exception e){e.printStackTrace ();} z~\Y*\f^Y3
5v5K}hx
cnR18NK
Utility.log(nFileLength); :i/uRR
x|U[|i,;
/}R*'y
return nFileLength; #mW#K
} TA>28/U#
*IV_evgM7
nx|b9W<
//保存下载信息（文件指针位置） "XWO#,Ue
private void write_nPos() zz1]6B*eX
{ 1D2Yued
try{ ,&0iFUwN_
output = new DataOutputStream(new FileOutputStream(tmpFile)); Or"+d 5
output.writeInt(nStartPos.length); :{M1]0NH
for(int i=0;i<nStartPos.length;i++) }o2e&.$4d
{ +~!\;71:f
// output.writeLong(nPos); oh.8WlI
output.writeLong(fileSplitterFetch.nStartPos); #6F/:j;
output.writeLong(fileSplitterFetch.nEndPos); Qcs>BOV~
} *S] K@g
output.close(); N)o/}@]6
} faPgp
catch(IOException e){e.printStackTrace ();} IT0 [;eqR
catch(Exception e){e.printStackTrace ();} \4"01:u'
} mH5[(?
95b65f
SZL('x,"^
//读取保存的下载信息（文件指针位置） mFW/xZwR,5
private void read_nPos() ?b3({P
{ QRAw#
try{ >SaT?k1E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %G/j+Pf
int nCount = input.readInt(); Vc?=cQ'c
nStartPos = new long[nCount]; &b!|Y
nEndPos = new long[nCount]; B|.8+Q
for(int i=0;i<nStartPos.length;i++) =`KV),\
{ G_)(?
nStartPos = input.readLong(); $\vTiS'
nEndPos = input.readLong(); ^eY% T5K
} ;/)u/[KAv
input.close(); MT(G=r8
} )sG/H8
catch(IOException e){e.printStackTrace ();} @;g|styh^
catch(Exception e){e.printStackTrace ();} 3FhkK/@
} 0mYKzJi
UY`U[#
H3Sfz'
private void processErrorCode(int nErrorCode) P#N@W_""YD
{ P=PVOt@ b
System.err.println("Error Code : " + nErrorCode); *|^}=ioj*
} 2/.I6IbL
drW}w+!
Nc[[o>/Cb
//停止文件下载 IM*T+iRKqF
public void siteStop() YCS8qEP&
{ dXewS_7
bStop = true; .|x"'3#
for(int i=0;i<nStartPos.length;i++) xe9V'wICp(
fileSplitterFetch.splitterStop(); x'hUw*
PBY^m+
mYw9lM
} Z9k"&F~u}
} ,n\'dMNii
//负责部分文件的抓取 y-=YXqj
**FileSplitterFetch.java {Tl|>\[P
*/ 8CN~o|uN
package NetFox; #Ss lH
q:X&)f
3tAX4DnYrq
import java.io.*; MaQ`7U5 |e
import java.net.*; v''F\V )
5"o)^8!>
uszH1@g'
public class FileSplitterFetch extends Thread { G'0]m-)dw
U?sio%`(
JtGBNz!"
String sURL; //File URL z4iZE*ZS
long nStartPos; //File Snippet Start Position ~ $QNp#dq
long nEndPos; //File Snippet End Position FNB4YZ6
int nThreadID; //Thread's ID VT~jgsY
boolean bDownOver = false; //Downing is over ~LufHbr
boolean bStop = false; //Stop identical , \ 6*fXc
FileAccessI fileAccessI = null; //File Access interface KQv97#n1
Ub9p&=]h
04wO9L;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >cM}M=4s
{ |*[#Iii'
this.sURL = sURL; ds|L'7
this.nStartPos = nStart; wV\.NQtS
this.nEndPos = nEnd; h0oe'Xov
nThreadID = id; r^v1_u,1I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /=K(5Xd
} /_D_W,#P
1$#1
O\+b1+&b3Y
public void run() xiy=D5N.=
{ uefrE53
while(nStartPos < nEndPos && !bStop) E'cI}q
{ gski:C
xS+!/pBf"Y
WS6;ad;|
try{ Mpx98xcO
URL url = new URL(sURL); 1'YUK"i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NA!?.zn
httpConnection.setRequestProperty("User-Agent","NetFox"); Jq*Q;}n
String sProperty = "bytes="+nStartPos+"-"; ;wa#m1
httpConnection.setRequestProperty("RANGE",sProperty); ~$jRn(2
Utility.log(sProperty); :SD#>eD0
U62Z ?nge%
<%N*IE"q
InputStream input = httpConnection.getInputStream(); PS3jCT
//logResponseHead(httpConnection); O<P(UT"
7DPxz'7):
?3y>K!D(A
byte[] b = new byte[1024]; GMlJM
int nRead; Gzc`5n{"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s=>^ 8[0O
{ OK(xG3T
nStartPos += fileAccessI.write(b,0,nRead); i<{:J -U|
//if(nThreadID == 1) Q%:Z&lgy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); INEE 37%
} K]&i9`>N
}Ud'j'QMy
Ce/D[%
Utility.log("Thread " + nThreadID + " is over!"); /V }Z,'+
bDownOver = true; FA{'Ki`
//nPos = fileAccessI.write (b,0,nRead); meYGIP:n
} v,!`A!{D
catch(Exception e){e.printStackTrace ();} ~NTKWRaR
} Zg9VkL6Z6
} CT/>x3o
fRjp(m
uN=f(-"
//打印回应的头信息 VA@
public void logResponseHead(HttpURLConnection con) vDIsawbHD
{ QIfP%,LT
for(int i=1;;i++) 88VI _<
{ /*(&Dmt>
String header=con.getHeaderFieldKey(i); D67z6jep(
if(header!=null) Md&K#)9,(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r72zWpF!Ss
Utility.log(header+" : "+con.getHeaderField(header)); b%].D(qBy
else 7ufTmz#j<
break; `SA1V),~
} P2F8[o!<
} d~q7!
(6i4N2
40O@a:q*
public void splitterStop() q2U?EP{8~
{ 32Wa{LG;2
bStop = true; 7NkMr8[}F
} LbuhKL}VN
KB{IWu
WidLUv
} y!T8(
,n`S ,
`neo.]
/* 0J6* U[
**FileAccess.java X o[GD`t
*//文件访问(定位，写) -EE}HUP)
package NetFox; P('bnDU
import java.io.*; vDyGxU!#\
fg/hUUl
l{Et:W%|
public class FileAccessI implements Serializable{ +F~B"a
;(rK^*`fO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Lb?0<
RandomAccessFile oSavedFile; I%{ 1K+V/
long nPos; LfJMSscfv
S0ReT*I
OVE?;x>n/1
public FileAccessI() throws IOException |xT'+~u
{ w,j;XPp
this("",0); }@~+%_;
} ]TN/n%\
/4}y2JVv)
cUO$IR)yL
public FileAccessI(String sName,long nPos) throws IOException e-nwR
{ !b$]D?=}
oSavedFile = new RandomAccessFile(sName,"rw"); pLM?m
this.nPos = nPos; nd[Ja_h
oSavedFile.seek(nPos); l5D4?`|
} GcG$>&,
8T8]gM
PAH#yM2Ic
public synchronized int write(byte[] b,int nStart,int nLen) yyGn<
{ Tfx-h)oP3
int n = -1; >*\yEH9"
try{ Qjd]BX;
oSavedFile.write(b,nStart,nLen); Zy|u5J
n = nLen; f ~bgZ
} P0RtS1A
catch(IOException e) >Bu_NoM
{ wxN&k$`a
e.printStackTrace (); S4rm K&
} DQ&\k'"\
Oc-ia)v1G
_:FD#5BZ1
return n; )P,pW?h$
} cM\BEhh
mex@~VK
+:W?:\
} t>x!CNb'C
WO6+r?0M2
b;nqhO[f}
/* P76gJ@#m
**SiteInfoBean.java wr~Qy4 ny
*/ [Fv_~F491
package NetFox; deJ/3\t
I:0dz:T7*
a-AA$U9hj
public class SiteInfoBean { *$3p3-
$M~`)UeV_
F"QJ)F
private String sSiteURL; //Site's URL c=^69>w
private String sFilePath; //Saved File's Path BU7QK_zT:
private String sFileName; //Saved File's Name c[$i)\0
private int nSplitter; //Count of Splited Downloading File Cq3Au%7
@H^\PH?pp
x=X&b%09
public SiteInfoBean() Kjpsz];
{//nSplitter的缺省值为5 lTVz'ys
//default value of nSplitter is 5 D_G]WW8
this("","","",5); gZ-:4G|J
} F%4N/e'L
#B q|^:nj
G&`5o*).bb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C =B a|Z
{ ?j)#\s2
sSiteURL= sURL; ?A~=.u@[d
sFilePath = sPath; kWs:7jiiu
sFileName = sName; iRqLLMrn
this.nSplitter = nSpiltter; R]RLy#j
SR`A]EC(V
6q7jI )l
} s@Loax6@B
/iJsa&W}
ad52a3deR
public String getSSiteURL() OL^DuoB4q
{ c8HETs1
return sSiteURL; wUfPnAD.'
} h 0)oQrY
NRk^Z)
O;T)u4Q&3
public void setSSiteURL(String value) %eGD1.R
{ M'oQ<,yW-
sSiteURL = value; Xn5LrLM&
} c{39,oF
j 20mZ
)q/brCq
public String getSFilePath() xK4E+^ b
{ |CK/-UG}
return sFilePath; )Y"t$Iw"
} `6LVXDR
3$BO=hI/-
jS5K:yx<
public void setSFilePath(String value) 7|Iq4@IT
{ <y"lL>JR
sFilePath = value; ey\(*Tu9
} +vPCr&40
Zm(}~C29
Uo[`AzD3
public String getSFileName() Ye^xV,U@
{ Q8h=2YL
return sFileName; 9WHarv2@
} ]eX(K5 A
rP/W,! 7:K
H>"P]Y)oX
public void setSFileName(String value) wy:euKB~
{ ?ZkVk=t?
sFileName = value; q^~w:$^U
} E~8J<gE
6\%#=GG
Jq+@%#G
public int getNSplitter() @[n%q.|VB
{ EJJ&`,q
return nSplitter; B*^QTJ
} L:jv%;DM
F$9+WS`c
1-R4A7+3
public void setNSplitter(int nCount) Bma.Uln
{ "IWL& cH3
nSplitter = nCount; w"A>mEex<
} "c![s%
} 9Z3Vf[n5\
eO{2rV45O
WckWX]};S
/* pwF])uf*{\
**Utility.java ~c\2'
*/ ;@n/gU
package NetFox; qVds 2
)Rj?\ZUR
cO-^#di
public class Utility { 0_t9;;y :
aDE}'d1qo
^HHT>K-m
public Utility() 8P2_/)|
{ lO}I>yo}\
|8{\j*3
2,.8oa(
} 4*UKR!sr
R]o2_r7N"}
//线程睡眠 q-e3;$
public static void sleep(int nSecond) CZ(fP86e
{ >-(,BfZ
try{ 2F ~SH
Thread.sleep(nSecond); ,rhNXx
} %B| Ca&
catch(Exception e) <S0gIg`)
{ NF7+Gp6?q
e.printStackTrace (); )xTu|V
} 5L\Im^
} @X_)%Y-^O
e^hI[LbNC
//日志 I3Ad+]v
public static void log(String sMsg) p >nKNd_aQ
{ B<,AI7
System.err.println(sMsg); Wa%p+(\<uB
} X C'|
<h`}I3Ao
=z}M(<G
public static void log(int sMsg) Ul:M=8nE%
{ &VVvZ@X;
System.err.println(sMsg); [kI[qByf
} ,4(m.P10
} WX$AOnEv
?nf4K/IjZ!
}/7rA)_
/* KoFWI_(b
**TestMethod.java YRj"]= 5N
*/ m .^WSy
package NetFox; ~vfPsaRh
M7neOQHq
ket"fXqJX
public class TestMethod { U#4>GO;A
a!;K+wL >
1c$ce+n~
public TestMethod() AHLXmQl
{ ///xx/weblogic60b2_win.exe Lx3`.F\mG
try{ L$[1+*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f5.Be%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;GZ'Rb
SiteFileFetch fileFetch = new SiteFileFetch(bean); zBqNE`
fileFetch.start(); t>"|~T$9
} <{.pYrn
catch(Exception e){e.printStackTrace ();} W1O Y}2kj
et`rPK~m
r#^uY:T%
} gE6{R+sp
S2$r 6T
eak+8URo
public static void main(String[] args) =n MAw&`
{ l D]?9K29
new TestMethod(); KocNJ TB
} fyv S1_
} @Sz7*p
点击下载更多相关资料