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)); /7nb,!~~l
} G~^r)fm_
for(int i=0;i<nEndPos.length-1;i++) fo*2:?K&
{ H1pO!>M
nEndPos = nStartPos[i+1]; /yDz/>ID\
} cz#rb*b
nEndPos[nEndPos.length-1] = nFileLength; 6y%qVx#!
} c)TPM/>(p
} *v jmy/3
"/*\1v9
N ,'GN[s
//启动子线程 B4c]}r+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -LoZs ru
for(int i=0;i<nStartPos.length;i++) 8`q:Gz=M\
{ rxgbV.tx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =r?hgGWe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |C;=-|
nStartPos,nEndPos,i); AW%#O\N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?>D+ge
fileSplitterFetch.start(); (Du@ S
} Zw 26
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IXMop7~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~rE|%o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V%7WUq
nEndPos = " + nFileLength); ~NrG` D}
// fileSplitterFetch[nPos.length-1].start(); U2tV4_ e
j\[dx^\=
)0.kv2o.
//等待子线程结束 }>pknc?
//int count = 0; Sxt"B
//是否结束while循环 7{e 4c
boolean breakWhile = false; fIx+ILs
P%V'4pc
k_L7 kvpt
while(!bStop) ~RW+GTe
{ |B?m,U$A!
write_nPos(); X:f UI4
Utility.sleep(500); h0*!;Z7
breakWhile = true; aD<A.Lhy
v+W&9>
j78i#}e
for(int i=0;i<nStartPos.length;i++) %~O,zs.2p
{ er("wtM
if(!fileSplitterFetch.bDownOver) .KB^3pOpx
{ &n}]w+w
breakWhile = false; X[-xowE-
break; YFLZ%(
} s[RAHU
} dc+>m,3$
if(breakWhile) |IeTqEu9
break; 7Kr*P<-G
{g'(~ qv
<prk8jSWV
//count++; OZb-:!m*
//if(count>4) FZ{h?#2?
// siteStop(); [SjqOTon{
} %+aCJu[k(z
(+w*[qHe
h"[AOfTE$
System.err.println("文件下载结束！"); MD}w Y><C
} f&NgS+<K$
catch(Exception e){e.printStackTrace ();} =J]&c?I
} A9KET$i@v
.Yamc#A-
m<<+
//获得文件长度 %8RrRW
public long getFileSize() JU4<|5H
{ NlA,'`,
int nFileLength = -1; oM X
try{ lF<]8m%F
URL url = new URL(siteInfoBean.getSSiteURL()); N~nziY*C,*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +RHS!0
httpConnection.setRequestProperty("User-Agent","NetFox"); ^rB8? kt
aj-Km`5r}
k%]3vRo<
int responseCode=httpConnection.getResponseCode(); z 4e7PW|
if(responseCode>=400) =Pyj%4Rs
{ $f$SNx)),
processErrorCode(responseCode); P7[h-3+^
return -2; //-2 represent access is error frm>4)9+
} lne|5{h
BwN0!lsF3
E'f{i:O"~
String sHeader; o@_q]/Mh
\,'m</o~,
:p1u(hflS
for(int i=1;;i++) 0G(/Wb"/
{ U"~>jZKk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D5gFXEeh
//Utility.log(in.readLine()); s-NX o
sHeader=httpConnection.getHeaderFieldKey(i); eFB5=)ld
if(sHeader!=null) CYf$nYR
{ H-!,yte
if(sHeader.equals("Content-Length")) 9sM!`Lz{
{ 6lZ3tdyNo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &Gc9VF]o
break; (fhb0i-
} 4V"E8rUL(
} zF@/K`
else j}#w)M
break; [DYQ"A=)d
} ]E{NNHK%2N
} _kC-dEGf!y
catch(IOException e){e.printStackTrace ();} SjK
catch(Exception e){e.printStackTrace ();} !K#qeY}
a)!o @
oe ~'o'
Utility.log(nFileLength); :ffY6L+
HRpte=`q
$o!zUH~'v
return nFileLength; Yz9owe8}[
} !@5 9)
x o;QCOH
;t)3F
//保存下载信息（文件指针位置） ~kV/!=
private void write_nPos() ~EW(Gs!=C
{ YByLoM*
try{ +l42Awl>K
output = new DataOutputStream(new FileOutputStream(tmpFile)); .S EdY:
output.writeInt(nStartPos.length); X hR4ru`
for(int i=0;i<nStartPos.length;i++) q#~ (/
{ &L3M]
// output.writeLong(nPos); ]|#+zx|/D
output.writeLong(fileSplitterFetch.nStartPos); "BAK !N$9
output.writeLong(fileSplitterFetch.nEndPos); RCJ|P~*
} IM*y|UHt
output.close(); g/4[N{Xf
} T%+#xl
catch(IOException e){e.printStackTrace ();} \-E^lIVF
catch(Exception e){e.printStackTrace ();} ??5Q)Erm1
} pG_;$8Hc
k``_EiV4t
yER(6V'\iQ
//读取保存的下载信息（文件指针位置） >k|5Okq g
private void read_nPos() ^"E^zHM(
{ L]7=?vN=8
try{ />C^WQI^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z>xmRs
int nCount = input.readInt(); rDtY[
nStartPos = new long[nCount]; K&u_R
nEndPos = new long[nCount]; 1pVS&0W
for(int i=0;i<nStartPos.length;i++) .C%<P"=J4h
{ D#aDv0b
nStartPos = input.readLong(); b\f O8{k
nEndPos = input.readLong(); #x@$lc=k3
} Nd4f^Y
input.close(); ]dVGUG8
} 4>YR{
catch(IOException e){e.printStackTrace ();} ]U?^hZ_
catch(Exception e){e.printStackTrace ();} <(#(hDwy
} 39c2pV[
*YI98
yHYsZ,GE
private void processErrorCode(int nErrorCode) . P viA
{ I]|Pq
System.err.println("Error Code : " + nErrorCode); oE@a'*.\
} ;T\%|O=Ke
hXw]K"
RIR\']WN
//停止文件下载 _1X!EH"
public void siteStop() BX/8O<s0
{ 2B1q*`6R
bStop = true; P.se'z)E
for(int i=0;i<nStartPos.length;i++) rE7G{WII
fileSplitterFetch.splitterStop(); PxX4[ P
LG0;#3YwH
TJd)K$O>
} 8bGd} (
} %X]jaX7
//负责部分文件的抓取 thh.A
**FileSplitterFetch.java R>|{N9
*/ Ng&%o
package NetFox; - nm"of\o
2YL?,uLS
4(n-_BS
import java.io.*; 1y&\5kB
import java.net.*; 1NFsb-<u
J6"9v;V
-]Bq|qTH[(
public class FileSplitterFetch extends Thread { >tS'Q`R
J`Q>3]wL
$GV7o{"&
String sURL; //File URL 'ycJMYP8
long nStartPos; //File Snippet Start Position ^S<Y>Nm]
long nEndPos; //File Snippet End Position Y>z>11yEB0
int nThreadID; //Thread's ID W.jGGt\<\
boolean bDownOver = false; //Downing is over YRk(u7:0
boolean bStop = false; //Stop identical D>r&}6<
FileAccessI fileAccessI = null; //File Access interface &A/]pi-\
0q
wSL}`CgU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O^PKn_OJ
{ G&SB-
this.sURL = sURL; 3d8L6GJ
this.nStartPos = nStart; [Y/} ^
this.nEndPos = nEnd; OF>mF~
nThreadID = id; 2>9C-VL2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1.JK33
} ZgJQ?S$D
Y|m+dT6
%Qgw7p4
public void run() ~Gp[_ %K
{ .<?GS{6 N
while(nStartPos < nEndPos && !bStop) yF:1( 4
{ 0JS?;fk
Tb}4wLu
Rh2+=N<X
try{ OKZV{Gja
URL url = new URL(sURL); 234p9A@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o 11jca|
httpConnection.setRequestProperty("User-Agent","NetFox"); Xq4O@V
String sProperty = "bytes="+nStartPos+"-"; E =67e=h
httpConnection.setRequestProperty("RANGE",sProperty); R-wp9^
Utility.log(sProperty); &AMl:@p9
mUC)gA/
PQt")[
InputStream input = httpConnection.getInputStream(); Mt|zyXyzX
//logResponseHead(httpConnection); SGRp3,1\4%
Jrf=@m\dk
KkyVSoD\
byte[] b = new byte[1024]; }Bh8=F3O Q
int nRead; Y Uc+0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pad*oPH,
{ &E F!OBR
nStartPos += fileAccessI.write(b,0,nRead); \sixI;-2
//if(nThreadID == 1) 2DrM3ZU8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9=M$AB
} ;+_:,_
Q}JOU
^e5=hH-%
Utility.log("Thread " + nThreadID + " is over!"); |i*37r6]=
bDownOver = true; u#fM_>ML
//nPos = fileAccessI.write (b,0,nRead); /62!cp/F/D
} P5V}#;v
catch(Exception e){e.printStackTrace ();} \7eUw,~Q>
} ,t744k')
} UgRiIQMq.
ztY}5A2`
VCfl`Aq'l
//打印回应的头信息 e]aDP1n3t
public void logResponseHead(HttpURLConnection con) nAato\mM
{ j_[tu!~
for(int i=1;;i++) +E+p"7
{ rKc9b<Ir
String header=con.getHeaderFieldKey(i); s^TZXCyF o
if(header!=null) FGJ1dBLr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =s{>Fsm1
Utility.log(header+" : "+con.getHeaderField(header)); *Q.>-J<S
else =BeygT^
break; Jr4Ky<G_i
} uZYF(Yu
} @bLy,Xr&
B@))8.h]
t+ TdLDJR
public void splitterStop() dQX6(Jj
{ 0> E r=,e
bStop = true; Dpac^ST
} <dNOd0e
3`?7<YJ
T<>,lQs(a
} E=Bf1/c\
Oszj$C(jF
:,7hWs
/* ttQGoUkj
**FileAccess.java m7V/zne
*//文件访问(定位，写) w.o@7|B1N
package NetFox; W i.&e
import java.io.*; VGN5<?PrN
>|=ts
H41?/U,{
public class FileAccessI implements Serializable{ 6_;icpN]
MchA{p&Ol
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {Mk6T1Bkq
RandomAccessFile oSavedFile; A{zN| S[
long nPos; (mB&m@-N
2pCaX\t
%2{ye
public FileAccessI() throws IOException Q{>k1$fkV
{ T763:v
this("",0); ?j.,Nw4FC
} R\f+SvE
3,w_".m`#
H8jpxzXv
public FileAccessI(String sName,long nPos) throws IOException 1GRCV8"Z^
{ >R_&Ouh:
oSavedFile = new RandomAccessFile(sName,"rw"); G_JA-@i%
this.nPos = nPos; 372rbY
oSavedFile.seek(nPos); TX/Xt7#R:
} ,p a {qne
/N.b%M]!
({_{\9O,3
public synchronized int write(byte[] b,int nStart,int nLen) c6]U E@A
{ 29b9`NXt
int n = -1; e9tjw[+A
try{ WU` rh^
oSavedFile.write(b,nStart,nLen); cjY-y-vO
n = nLen; ,`Z1m o>n
} gH vZVC[b
catch(IOException e) kD%( _K5
{ i]4I [!
e.printStackTrace (); n@i HFBb
} WwFm*4{[o
r6qj7}\
z<;HQX,
return n; Or+U@vAnk
} _[3D
}X6m:#6
$%Kfq[Q
} BO&bmfp7,
3hH<T.@)
=nS3p6>rZ
/* ;'K5J9k
**SiteInfoBean.java gf@:R'$:+
*/ N+xP26D8
package NetFox; WH}y"W
{P./==^0
aXYY:;
public class SiteInfoBean { 6gE7e|+
Vb_4f"
RqrdAkg
private String sSiteURL; //Site's URL P@B]
private String sFilePath; //Saved File's Path x9g#<2w8
private String sFileName; //Saved File's Name p6@)-2^
private int nSplitter; //Count of Splited Downloading File n\DV3rXI9
{tZ.v@
m s\}
public SiteInfoBean() {\5
{//nSplitter的缺省值为5 ~ 7s!VR
//default value of nSplitter is 5 )10+@d
this("","","",5); # W']6'O
} teF9Q+*~
\b x$i*
2ilQXy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vE?G7%,
{ aFYIM`?(
sSiteURL= sURL; F41=b4/
sFilePath = sPath; S\=Nn7"
sFileName = sName; `^&OF uee
this.nSplitter = nSpiltter; ##*3bDf$-5
R 9\*#c
3pKQ$\u
} 6_Y,eL]"
D,feF9
?tbrbkx
public String getSSiteURL() wHy!CP%
{ fZF@k5*\
return sSiteURL; HZge!Yp<
} }}~|!8
C'x&Py/#
:o3N;*o>)0
public void setSSiteURL(String value) l_p2Riv
{ ,J@
sSiteURL = value; GTd,n=
} #6=
rILYI;'o
lf,5w
public String getSFilePath() ?caSb=f
{ [W&T(%(W-
return sFilePath; 4r}51 N\
} ?@86P|19
;Y, y4{H3
ZECfR>`x
public void setSFilePath(String value) e^voW"?%
{ <5051UEu
sFilePath = value; 2+XAX:YD
} WyiQoN'q
|6-nbj
2>%=U~5
public String getSFileName() HRA|q
{ x%B%f`]8
return sFileName; GbI/4<)l}
} 59u}W 0
l/5 hp.
[/r(__.
public void setSFileName(String value) ob]w;"
{ XCQs2CHt
sFileName = value; h*\%vr
} PJ#,2=n~
e0 ecD3
5 qA'
public int getNSplitter() |G<|F`Cj
{ ccxNbU
return nSplitter; h?U O&(
} i%?*@uj
*;FdD{+
}GM'.yutX
public void setNSplitter(int nCount) (ZlU^Gw#UB
{ ~xTt204S
nSplitter = nCount; -9?]IIVb
} u ga_T
} 6u6x
A#,ZUOPGH
;'1d1\wiDQ
/* V7/Rby Q
**Utility.java [}m[)L\
*/ gX@aG9
package NetFox; UiNP3TJ'L
*T1_;4i
{!`6zBsP
public class Utility { #vlgwA
lOp`m8_=
8@R|Km5h
public Utility() Fr-SvsNFB
{ 7tp36TE
l[J8!u2Xp
P+}h$_x
} j~MI<I+l[
WIGi51yC.x
//线程睡眠 rJB}qYD
public static void sleep(int nSecond) Z_NCD`i;
{ 6]wIG$j
try{ ,esmV-
Thread.sleep(nSecond); ar,7S&sH
} \U_@S.
catch(Exception e) eO1lnO|
{ !VpoZ
e.printStackTrace (); t{>q|0
} -?a 26o%e
} ]M3yLYK/P
k?}Zg*
//日志 U0+-W07>
public static void log(String sMsg) MQ2_`pi
{ mE[y SrV
System.err.println(sMsg); V]^$S"Tv
} X8\GzNE~R
An@t?#4gxi
ssL\g`xe
public static void log(int sMsg) xSu >
{ F0# 'WfM#
System.err.println(sMsg); *zLMpL_
} 7:@'B|
} AXB7oV,xt
Ys7]B9/1O
y{Q {'De
/* I1J-)R+
**TestMethod.java AZ<=o
*/ PvL[e"p
package NetFox; H?w6C):]
Y/oHu@ _
+C)~bb*
public class TestMethod { i#O SC5ZI
UxBpdm%dvP
'ga/
public TestMethod() VU#7%ufu&
{ ///xx/weblogic60b2_win.exe jiGTA:v
try{ EM_d8o)`B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gM]:Ma
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d zMb5puH
SiteFileFetch fileFetch = new SiteFileFetch(bean); MK*r+xfSae
fileFetch.start(); Q{/Ef[(a@
} TqQ[_RKg2
catch(Exception e){e.printStackTrace ();} Ort(AfW
+7a6*;\ y
76SXJ9@x
} !IR6 ,A\
@VI@fN
"M0z(NkH
public static void main(String[] args) qgB_=Q#E
{ QV8g#&z
new TestMethod(); -g<oS9
} n+p }\msH
} <ZW-QN4
点击下载更多相关资料