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)); \as^z!<
} 'GJ'Vli
for(int i=0;i<nEndPos.length-1;i++) pk&;5|cCD
{ i[\`]C{gf
nEndPos = nStartPos[i+1]; 7yDWcm_y
} G$HXc$OY
nEndPos[nEndPos.length-1] = nFileLength; Y8$,So>~
} _,C>+dv)
} 0wlKBwf`J
LE1#pB3TG
]=EYju@
//启动子线程 @UG%B7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o[ua$+67E
for(int i=0;i<nStartPos.length;i++) kbHfdA
{ JJ=%\j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7B"*< %<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $Z2Y%z6y
nStartPos,nEndPos,i); 4{Q{>S*h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ivb?B,Lz0
fileSplitterFetch.start(); K>a+-QWK3
} "{igrl8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \dzHG/e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =8!FY"c*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Munal=wL
nEndPos = " + nFileLength); 3gcDc~~=
// fileSplitterFetch[nPos.length-1].start(); F4|Z:e,Hr
v.~uJ.T
j$u=7Z&E
//等待子线程结束 [G=+f6 a
//int count = 0; ^jiYcg@_[
//是否结束while循环 <8[y2|UBt
boolean breakWhile = false; wP: w8O
rCTH 5"
l)^sE)
while(!bStop) 'Rg6JW\
{ "Om4P|
write_nPos(); K~I%"r|l
Utility.sleep(500); sPod)w?e
breakWhile = true; D')m8:>
4*vV9*'!
9jC>OZ0s
for(int i=0;i<nStartPos.length;i++) +"HLx%k
{ F}C.F
if(!fileSplitterFetch.bDownOver) TcP (?v
{ >2%*(nL
breakWhile = false; `BA,_N|6
break; N;A#K7A[@
} ;:/<XfZ
} !pMp n%r<]
if(breakWhile) k ='c*`IE
break; 2Kg+SLU[~
[!k#au+#c
13X\PO'9
//count++; l^$8;$Rq
//if(count>4) PI5a'k0F
// siteStop(); Y4 <
} XC D&Im
-hpJL\ng
Q#2gjR r
System.err.println("文件下载结束！"); ;<9dND
} ~}g"Fe
catch(Exception e){e.printStackTrace ();} hA0g'X2eC
} g+xA0qW
06dk K)`
>kLUQ%zE@
//获得文件长度 Gop;!aV1*
public long getFileSize() u0M? l
{ < SIe5"{
int nFileLength = -1; vp>,}nx4
try{ g3`:d)|
URL url = new URL(siteInfoBean.getSSiteURL()); 4.^1D';(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D@]*{WO
httpConnection.setRequestProperty("User-Agent","NetFox"); {r$n $
"0&+`7
X9YYUnR2
int responseCode=httpConnection.getResponseCode(); $<~o,e-4
if(responseCode>=400) oOU?6nq
{ fF\s5f#:
processErrorCode(responseCode); )U~,q>H+ %
return -2; //-2 represent access is error Y~j)B\^{
} '^!1AGF
aIA9rn
%nmD>QCe
String sHeader; Jbmi[`O
YXdd=F
'|9fDzW"]
for(int i=1;;i++) rerl-T<3
{ (q@DBb4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )G a%Eg9
//Utility.log(in.readLine()); _Kw<4$0<p
sHeader=httpConnection.getHeaderFieldKey(i); B}(+\Q$I
if(sHeader!=null) [YsN c
{ 2[#7YWs
if(sHeader.equals("Content-Length")) CXZO
{ |?tUUT!`t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2GHmA_7P
break; '}Tf9L%
} POl[]ni=>
} SR4cR)Iz
else "K7{y4
break; 4]VoIUIuN
} mo$`a6[h<
} |BO!q9633V
catch(IOException e){e.printStackTrace ();} lhyWlO
catch(Exception e){e.printStackTrace ();} ?0U.1N
?0{8fGM4
KXAh0A?&+
Utility.log(nFileLength); exnFy-
^o*$OM7x
[|XMR=\>
return nFileLength; ?_!} lg
} ;Tn$c70
+;H-0Q5
4t%g:9]vr
//保存下载信息（文件指针位置） g^V4+3v|a'
private void write_nPos() rr@S|k:|
{ ~.FZF
try{ zB8 @Wl
output = new DataOutputStream(new FileOutputStream(tmpFile)); " ^t3VjN
output.writeInt(nStartPos.length); u+&t"B
for(int i=0;i<nStartPos.length;i++) -UHa;WH
{ @F+zME
// output.writeLong(nPos); S#kA$yO
output.writeLong(fileSplitterFetch.nStartPos); '`/Qr~]
output.writeLong(fileSplitterFetch.nEndPos); Vm_waa
} U^ecg{
output.close(); ,:Q+>h
} *kliI]BF]
catch(IOException e){e.printStackTrace ();} @Qlh
catch(Exception e){e.printStackTrace ();} rYp]RX>
} <|Pw*L$
x9,X0JO
x8#bd{
//读取保存的下载信息（文件指针位置） wNHvYulI
private void read_nPos() epcBr_}
{ wVSk.OOB
try{ KfSI6 Y_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,-C%+SC
int nCount = input.readInt(); y@5{.jsr_
nStartPos = new long[nCount]; .d^XM
nEndPos = new long[nCount]; !,}F2z?4c
for(int i=0;i<nStartPos.length;i++) CSUXa8u7
{ lk$@8h$vS
nStartPos = input.readLong(); 9K9{$jN~
nEndPos = input.readLong(); *0K@^Db-
} QO0#p1fom'
input.close(); q&j4PR{
} <vMdfw"(
catch(IOException e){e.printStackTrace ();} 4\cJ}p}LZ{
catch(Exception e){e.printStackTrace ();} ~HW}Wik
} f.Uvf^T}2
mHm"QBa!
&2~c,] 9C
private void processErrorCode(int nErrorCode) O?6ph4'
{ 8"fZ>XQ
System.err.println("Error Code : " + nErrorCode); tp6-j`7u
} <B }4}-}
!e+^}s
rF/k$_bFt
//停止文件下载 M<4tjVQ6
public void siteStop() $jpAnZR- /
{ {0&'XA=j
bStop = true; S? -6hGA j
for(int i=0;i<nStartPos.length;i++) z1-JoZ
fileSplitterFetch.splitterStop(); TqvgCk-
f1hjU~nJ
zNZ"PYh<u
} j}uVT2ZE%
} *J ]2"~_.
//负责部分文件的抓取 Ju0W
**FileSplitterFetch.java F8c^M</
*/ =B+^-2G8
package NetFox; s+EJXoxw
&!kD81?Mm
8lI'[Y?3.
import java.io.*; TJ&Z/k3-
import java.net.*; ([mC!d@a
\:'|4D]'I
h{J=Rq
public class FileSplitterFetch extends Thread { aSN"MTw.
0q@U>#
Z=L~W,0'
String sURL; //File URL c"|4'#S
long nStartPos; //File Snippet Start Position 1<Z~Gw4
long nEndPos; //File Snippet End Position 4iDlBs+
int nThreadID; //Thread's ID >~nc7j u
boolean bDownOver = false; //Downing is over d0b`qk @4
boolean bStop = false; //Stop identical L.cGt"{
FileAccessI fileAccessI = null; //File Access interface ~{8X$xs
ySS kw7
uxxS."~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e\9H'$1\
{ U2lDTRt
this.sURL = sURL; Vb _W&Nwd
this.nStartPos = nStart; l"C)Ia&/
this.nEndPos = nEnd; m(B,a,g<
nThreadID = id; */T.]^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eJ=K*t|
} /^m3?q[a
n1"QHA
[K*>W[n
public void run() q1|! oQ
{ X-Yy1"6m1
while(nStartPos < nEndPos && !bStop) l6[0i
{ xE[CNJ%t^,
@(~m.p|
eSC69mfD
try{ p+t79F.js
URL url = new URL(sURL); PB W.nm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B9Ha6kj
httpConnection.setRequestProperty("User-Agent","NetFox"); }'"4q
String sProperty = "bytes="+nStartPos+"-"; #dd-rooQuD
httpConnection.setRequestProperty("RANGE",sProperty); C6!P8qX
Utility.log(sProperty); B!;qz[]I
-F]0Py8(
FL,av>mV
InputStream input = httpConnection.getInputStream(); l'K3)yQEJ
//logResponseHead(httpConnection); uB`H9
wva| TZ
:k-(%E](
byte[] b = new byte[1024]; VSxls
int nRead; U1.w%b,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K;n5[o&c
{ >z,SN
nStartPos += fileAccessI.write(b,0,nRead); 6F@2:]W
//if(nThreadID == 1) *Dz<Pi^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'QMvj` -
} &3o[^_Ti
|x Nd^
7jf%-X
Utility.log("Thread " + nThreadID + " is over!"); DKvNQ:fI>9
bDownOver = true; Q9\6Pn ]T
//nPos = fileAccessI.write (b,0,nRead); ,.g9HO/R1
} m9&MTRD\
catch(Exception e){e.printStackTrace ();} #VLO6
} XW^Sw;[efZ
} ]Uy cT3A
b6LwKUl
B!z-O*fLE1
//打印回应的头信息 _LOV&83O(
public void logResponseHead(HttpURLConnection con) {eQ')f
{ -t5DcEAb$
for(int i=1;;i++) Mzbbr57n
{ B <CK~ybY
String header=con.getHeaderFieldKey(i); WX2w7O'R
if(header!=null) J[?7`6\M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ](z?zDk
Utility.log(header+" : "+con.getHeaderField(header)); bSKe@4C
else ]xYm@%>6
break; HgY#O r(
} h/AL`$
} 1>$}N?u:T
`4&a"`&$
>o#^)LN
public void splitterStop() ~kkwPs2V
{ !alO,P%>r
bStop = true; 6pKb!JJ
} !R`)S7!
w|;kL{(W
S>'S4MJE`
} _kJ?mTk
xIrRFK9[Q
<]/z45?
/* ,J(+%#$UT
**FileAccess.java cl4Vi%
*//文件访问(定位，写) 4Y=sTXbFt
package NetFox; y*AB=d^
import java.io.*; 2u> [[U1:
#fb <\!iza
rl<!h5
public class FileAccessI implements Serializable{ d- wbZ)BR
&>0ape
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +mr\AAFn
RandomAccessFile oSavedFile; @`hnp:
long nPos; JLZ[sWP='
~I+}u]J
q,W6wM;,E
public FileAccessI() throws IOException *>ilT5q
{ w^.^XK4v.
this("",0); t]j4PNzn
} @ k`^Z5tN
Dn}Wsd=
!JkH$~
public FileAccessI(String sName,long nPos) throws IOException |<YoH$.
{ `D#3
oSavedFile = new RandomAccessFile(sName,"rw"); <K#]1xCA
this.nPos = nPos; [qMFLY$
oSavedFile.seek(nPos); v7L}I[f
} K~?M?sa
Tt0:rQ.
|&>!"27;w
public synchronized int write(byte[] b,int nStart,int nLen) '+ 8.nN
{ 2Sq+w;/
int n = -1; frYPC Irj
try{ 6]#\|lds1
oSavedFile.write(b,nStart,nLen); !A6l\_
n = nLen; c1,dT2:=
} !Gphs`YI
catch(IOException e) P@u&~RN9f+
{ Rilr)$
e.printStackTrace (); 9O%4x"*PO
} )ny,vcU]
)ZU=`!4
L 1fK
return n; V?k"BU
} OZw<YR
7\q_^
s 4Mi9h_
} 05|,-S
wc-ll&0Z
qlUw;{;p
/* 6iozb~!Rr
**SiteInfoBean.java BBub'
*/ Qe~2'Hw#9
package NetFox; Qoj}]jve
V!'N:je
/$IF!q+C
public class SiteInfoBean { is3nLm(
%PsDS
QSn%~o05
private String sSiteURL; //Site's URL O$><E8q
private String sFilePath; //Saved File's Path NjTVinz
private String sFileName; //Saved File's Name sH^?v0^a
private int nSplitter; //Count of Splited Downloading File h-XMr_F
wGqQR)a
_t:l:x.;T
public SiteInfoBean() a=55bEn
{//nSplitter的缺省值为5 ~~.v*C[
//default value of nSplitter is 5 U#B,Q6~
this("","","",5); YzcuS/~x
} :qx>P_&y}z
Z66b>.<8
[7gyF}*;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Kb_R "b3v
{ cU y,q]PO
sSiteURL= sURL; "CEy r0h
sFilePath = sPath; a.|4`*1[;
sFileName = sName; JlR'w]d M,
this.nSplitter = nSpiltter; $RQ7rL3g{
&h7q=-XU
,_66U;T
} mGQgy[gX
N.J;/!%!
Tl#Jf3XY}
public String getSSiteURL() XFeeNcqF
{ 2p(M`@
return sSiteURL; 8F$b/Z
} q\qV~G`
23/!k}G"
vT<q zN
public void setSSiteURL(String value) /`iBv8!
{ &`a$n2ycy
sSiteURL = value; tQ7DdVdix
} lu^c^p;
(D'Z4Y
wz*QB6QtU
public String getSFilePath() 2a;vLc4
{ i^{.Q-
return sFilePath; c<V.\y0x
} UarU.~Uqi
WUid5e2
/j]r?KAzw
public void setSFilePath(String value) @!\g+z_"
{ p{j }%)6n
sFilePath = value; @:@0}]%z9
} -jB1tba
oZO6J-ea
/EUv=89{!
public String getSFileName() eNlE]W,=
{ Sti)YCXH
return sFileName; yQ4]LyS
} K\&A}R
{xw*H<"f<
'0|AtO77
public void setSFileName(String value) "C$z)
{ d"nz/$
sFileName = value; j.$#10*:
} lz!F{mR
s-eC')w~E
0s = h*"[
public int getNSplitter() 0&U,WA
{ JMu|$"o&{
return nSplitter; %S8e:kc6
} UA[2R1}d
#q~SfG
1<]g7W
public void setNSplitter(int nCount) ,ZcW+!
{ zCD?5*7
nSplitter = nCount; 07"dU
} v{ .-x\;
} 9&}`.Py
dtQ>4C"N
\4wM8j
/* m",wjoZe*
**Utility.java g$~3@zD
*/ WYTeu "
package NetFox; XG"&\FL{T
Q>nq~#3?
&0Zn21q
public class Utility { Ebp^-I9.d
8NJ(l
@<--5HbX
public Utility() Nt#zr]Fz
{ TH2D;uv
.+7GecYz
:g3n [7wR
} ]Ff"o7gT
(LPMEQhI:
//线程睡眠 P}o:WI4.cB
public static void sleep(int nSecond) \)VV6'zih
{ p_Fc:%j>
try{ SN|EWe^
Thread.sleep(nSecond); (yE?)s
} XOO!jnQu
catch(Exception e) St&xe_:^<
{ ~.M{n&NM
e.printStackTrace (); bD<[OerG
} 9|T%q2O
} nMD^x
ahkSEE{
//日志 M#on-[
public static void log(String sMsg) 693J?Yah[
{ $rDeI-)S
System.err.println(sMsg); %'j)~
} s z/7cLo
JwbC3t):@
x^}kG[s
public static void log(int sMsg) i]*Wt8~!
{ (7x5
System.err.println(sMsg); 6%NX|4_
} >`p`^:
} )JE;#m0q
S pDVD
!8vHN=)z
/* ys:1%D,,_
**TestMethod.java z %` \p
*/ T%K(opISc(
package NetFox; XJsHy_6
=)m2u2c M
UiA\J
public class TestMethod { ~%_$e/T
h@FDP#H
xh[Mmq/R
public TestMethod() HDYr?t~V
{ ///xx/weblogic60b2_win.exe CfQOG7e@
try{ ./mh9ax
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?hvPPEJf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j$^3
SiteFileFetch fileFetch = new SiteFileFetch(bean); dlN(_6>b
fileFetch.start(); aOfL;I
} #gi0FXL
catch(Exception e){e.printStackTrace ();} -WwFUm
< i*v
O5{!CT$
} p*F&G=ZE
n>jb<uz
33|>u+
public static void main(String[] args) OBi9aFoQ
{ _)Q)tOW
new TestMethod(); O^|dc=
} 2hAu~#X
} =v=a:e
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