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)); Q2HULz{
} oCR-KR>{Q
for(int i=0;i<nEndPos.length-1;i++) g xf|L>=
{ T!pjv8y@R
nEndPos = nStartPos[i+1]; [sweN]b6F
} xXm:S{I
nEndPos[nEndPos.length-1] = nFileLength; SM@RELA'Lb
} ^VAvQ(b!:i
} +\@WOs
sPUn"7
K^fH:pV
//启动子线程 L fx$M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %?~`'vYoi
for(int i=0;i<nStartPos.length;i++) D?<R5zp
{ cp\A xWtUZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +ZxG<1&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0'O*Y ]h+
nStartPos,nEndPos,i); )i{B:w\ ^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X`E3lgfqT
fileSplitterFetch.start(); gjnTG:}}}+
} .ECT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L4C_qb k;:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H^\2,x Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =f*Wj\
nEndPos = " + nFileLength); _]~= Kjp
// fileSplitterFetch[nPos.length-1].start(); 0zvA>4cq)
,@*Srrw
Wu9))Ir
//等待子线程结束 #Z.2g].
//int count = 0; DHnu F@M
//是否结束while循环 [J71aH
boolean breakWhile = false; K=`;D
n'-?CMH`
d:V6.7>,
while(!bStop) 2UGnRZ8:1Y
{ v1Wz#oP
write_nPos(); ]E/~PV
Utility.sleep(500); /K2=GLl;
breakWhile = true; WFBVAD
`[*nUdG
4v("qNw#
for(int i=0;i<nStartPos.length;i++) I/ q>c2Pw$
{ h72#AN
if(!fileSplitterFetch.bDownOver) ?U;KwS]%
{ m2o)/:
breakWhile = false; ")cJA f
break; ZSo#vQ
} F3L'f2yBG
} a7Fc"s*
if(breakWhile) Z[{k-_HgAm
break; DfJHH)Ry}
`0qBuE_^h
[`eqma
//count++; kA1C&
//if(count>4) #kt3l59Ty
// siteStop(); q0l=S+0
} jbU=D:|
xc HG5bg|
l1h;ng6
System.err.println("文件下载结束！"); O0Vtvbj
} Ym WVb
catch(Exception e){e.printStackTrace ();} 2W_p)8t>b
} JXBTd=r_oM
g,0u_$U
)O~V3a
//获得文件长度 3bGJ?hpp
public long getFileSize() m<DiYxK
{ _ `RCY^t
int nFileLength = -1; Snav)Hb'
try{ L:(>ON
URL url = new URL(siteInfoBean.getSSiteURL()); ?1G7=R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O"<W<l7Q
httpConnection.setRequestProperty("User-Agent","NetFox"); !)}3[h0
I,:R~^qJ8v
38[ko3
int responseCode=httpConnection.getResponseCode(); qXH\e|
if(responseCode>=400) D]s8w
{ $\DOy&e
processErrorCode(responseCode); J9kmIMq-C
return -2; //-2 represent access is error Wxi|(}
} @"\j]ZEnY
Dj~]]
99\;jz7
String sHeader; JE<zQf(&
*7ggw[~
b~1]}9TJ
for(int i=1;;i++) PyS~2)=B
{ B4<W%lm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RO([R=.`/
//Utility.log(in.readLine()); TH`zp]0
sHeader=httpConnection.getHeaderFieldKey(i); ^+ hJ& 9W
if(sHeader!=null) lO)0p2
{ wO&edZ]zb^
if(sHeader.equals("Content-Length")) X/ \5j
{ d"1DE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qm.30 2
break; fVU9?^0/)9
} 6evW O!
} )]=1W
else = }&@XRLJ
break; jL|y4
} b)SU8z!NV&
} w/L^w50pt
catch(IOException e){e.printStackTrace ();} rcC}4mNe
catch(Exception e){e.printStackTrace ();} PJ=N.xf}
%7X<:f|N8x
=1JS6~CTLN
Utility.log(nFileLength); 6N%fJ
[|=#~(yYQ
n>)'!
return nFileLength; & *^FBJEa.
} kHO2&"6
.%.kEJh`
qfO=_z ES
//保存下载信息（文件指针位置） +s*OZ6i [
private void write_nPos() X>[x7t:
{ ^V DJGBk
try{ D# $Fj
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0Cox+QJt
output.writeInt(nStartPos.length); NZJ:@J=-
for(int i=0;i<nStartPos.length;i++) `A]CdgA
{ ?e`4 sf_~
// output.writeLong(nPos); @>wD`<U|
output.writeLong(fileSplitterFetch.nStartPos); <Rs#y:
output.writeLong(fileSplitterFetch.nEndPos); |Ef\B]Ns
} BFU6?\r
output.close(); hi{#HXa
} 7,i}M
catch(IOException e){e.printStackTrace ();} m])!'Pa(=
catch(Exception e){e.printStackTrace ();} >-2eZ(n)"
} WIytgM
*K9I+t"g
Zz"b&`K
//读取保存的下载信息（文件指针位置） l7 +#gPA
private void read_nPos() 4G:I VK9
{ _RLx;Tn)L
try{ }(g`l)OX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `EV" /&`
int nCount = input.readInt(); ]=s!cfu
nStartPos = new long[nCount]; [DW}z
nEndPos = new long[nCount]; dQoZhE
for(int i=0;i<nStartPos.length;i++) 4H7 3a5f
{ =h?Q.vad
nStartPos = input.readLong(); !Gv*iWg
nEndPos = input.readLong(); <b-BJ2],k
} a,o>E4#c
input.close(); ?;{fqeJz
} 'Zq$W]i
catch(IOException e){e.printStackTrace ();} s m42
catch(Exception e){e.printStackTrace ();} J{GtH[
} @WppiZ$
U6hT*126
Wvhg:vup
private void processErrorCode(int nErrorCode) A),nkw0X
{ #n=b*.
System.err.println("Error Code : " + nErrorCode); KY)rkfo B
} Zk#^H*jgx
VZOf|o
-1tdyCez
//停止文件下载 -rU~
public void siteStop() V:M$-6jv
{ "W_C%elg
bStop = true; P);:t~
for(int i=0;i<nStartPos.length;i++) ]!>ThBMa
fileSplitterFetch.splitterStop(); "J0,SFu:
9m2_zfO[w
S ("Zzq`
} .s4hFB^n
} SZOcFmC?
//负责部分文件的抓取 QjW7XVxB#N
**FileSplitterFetch.java -Yaw>$nJ
*/ O<3i6
package NetFox; 'qTMY*
> ,L'A;c}
,`7;S,f
import java.io.*; =-M)2&~L~
import java.net.*; j@c fR
\NYtxGV[Z
&9CKI/K:
public class FileSplitterFetch extends Thread { 1a#oJU
yVThbL_YJ
[\o+I:,}wi
String sURL; //File URL 1vTncU!
long nStartPos; //File Snippet Start Position WZk\mSNV
long nEndPos; //File Snippet End Position q% Eze
int nThreadID; //Thread's ID |Rr^K5hmD
boolean bDownOver = false; //Downing is over &a?&G'?
boolean bStop = false; //Stop identical &"dT/5}6
FileAccessI fileAccessI = null; //File Access interface _VU/j9<+
ETP}mo
"7R"(.~>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <!.'"*2
{ T^-fn
this.sURL = sURL; t#+X*'/
this.nStartPos = nStart; R5LzqT,/N:
this.nEndPos = nEnd; 0\tk/<w2
nThreadID = id; 9wP_dJvb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $!c)%qDq
} %Z-^Bu8;y
i2{xW`AcUh
fP`g#t)4Tu
public void run() /^~3Ib8Fw+
{ V/Hjd`n)`i
while(nStartPos < nEndPos && !bStop) T`g.K6$b
{ /#Y)nyE
_A*5BAB:h(
~mc7O
try{ $'3`$
URL url = new URL(sURL); T>(nc"(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <dx xXzLT
httpConnection.setRequestProperty("User-Agent","NetFox"); uX{n#i,~L
String sProperty = "bytes="+nStartPos+"-"; V\zf yH\~
httpConnection.setRequestProperty("RANGE",sProperty); &x{CC@g/
Utility.log(sProperty); N9r}nqCN
^5TSo&qZ
YmM+x=G:
InputStream input = httpConnection.getInputStream(); :>to?~Z1
//logResponseHead(httpConnection); 3kFOs$3
!|`G<WD
P F!S
byte[] b = new byte[1024]; "}UJ~ j).
int nRead; -SaH_Nuj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E 3b`GRay
{ J=4R" _yo
nStartPos += fileAccessI.write(b,0,nRead); V,bfD3S3
//if(nThreadID == 1) oxE'u<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A87JPX#R?
} SU OuayE
U0'>(FP~2
U'S}7gya
Utility.log("Thread " + nThreadID + " is over!"); #%k!`?^fbK
bDownOver = true; 3*$A;%q
//nPos = fileAccessI.write (b,0,nRead); gK/mm\K@
} t>|Y-i3cb
catch(Exception e){e.printStackTrace ();} |R:gu\gG
} ?Y2ZqI
} W R@=[G#TJ
Ed9ynJ~)X
D.o|pTZ
//打印回应的头信息 a&~_ba+
public void logResponseHead(HttpURLConnection con) kH1hsDe|&y
{ Z<ozANbk
for(int i=1;;i++) Z^,C><Yt
{ `m?%{ \
String header=con.getHeaderFieldKey(i); /*g3TbUs
if(header!=null) !7!xJ&/V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2<wuzP|
Utility.log(header+" : "+con.getHeaderField(header)); T6JN@:8
else ^RytBwzKM
break; 8RWfv}:X
} V0 x[sEW
} r H;@N
j?%^N\9
ZB GLwe
public void splitterStop() 8 $0D-z
{ Zpg/T K
bStop = true; pDb5t>
} "P HkbU
~C=I{qzF+
$A"kHS7T
} ?>5[~rMn
m\`dLrPX4j
/ pzdX%7
/* /PG+ s6
**FileAccess.java K[0.4+
*//文件访问(定位，写) D"0:n.
package NetFox; ~4h<nc
import java.io.*; e*p7(b-
=LV7K8FSd
#j -bT4!
public class FileAccessI implements Serializable{ m7wD#?lm
j_*$Avy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jY%&G#4
RandomAccessFile oSavedFile; Bz<T{f
long nPos; 4Gs#_|!
"V-k_d "
3~Od2nk(x
public FileAccessI() throws IOException \7PPFKS
{ y\Kr@;q0w
this("",0); iSu7K&X9q
} RUqN,C,m5I
a5=8zO#%g
"s!!\/^9C
public FileAccessI(String sName,long nPos) throws IOException \MBbZB9@
{ >QO^h<.>
oSavedFile = new RandomAccessFile(sName,"rw"); _+PiaJ&'
this.nPos = nPos; #\s*>Z
oSavedFile.seek(nPos); |{W4JFKJ
} G2 A#&86J{
O O?e8OU
"%fh`4y3\
public synchronized int write(byte[] b,int nStart,int nLen) ws8@yr<R
{ +GCN63nX
int n = -1; -n&g**\w
try{ -!MrG68
oSavedFile.write(b,nStart,nLen); R<.<wQ4I
n = nLen; Pyh+HD\
} j1{|3#5V
catch(IOException e) oV"d%ks
{ ]<b$k
e.printStackTrace (); 0K/Pth"*
} MzjV>.
s~e<Pr?yu
GL;@heP
return n; j>jZg<}J
} Ku;|Dz/=o
DUH\/<^g
x/~qyX8vo
} ]xGo[:k|E
F6>K FU8
8vQGpIa,
/* p7 s#j
**SiteInfoBean.java eu=G[>
*/ AI KLJvte
package NetFox; q5 eyle6
m$N`Xj
Br/qOO:n$}
public class SiteInfoBean { [/dGOl+
F`!B!uY
L8OW@)|
private String sSiteURL; //Site's URL b#ga
private String sFilePath; //Saved File's Path 5)712b(&
private String sFileName; //Saved File's Name NUxOU>f
private int nSplitter; //Count of Splited Downloading File -CV_yySc
WFWQ;U{|
d)@Hx8
public SiteInfoBean() &6]+a4
{//nSplitter的缺省值为5 ed3d 6/%HR
//default value of nSplitter is 5 pypW
this("","","",5); 'XW[uK]w)
} { 'A`ram
mL5Nu+#
$;O-1# ]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D$X9xtT
{ So?.V4aD_
sSiteURL= sURL; )"( ojh
sFilePath = sPath; eZ>KA+C[
sFileName = sName; Q1ox<-
this.nSplitter = nSpiltter; S8=Am7D]1
-dRnozs6W
hKkUsY=R
} C\-Abqc
X?6E0/r&9
M't~/&D#
public String getSSiteURL() (I<]@7>
{ cL+--$L
return sSiteURL; F4P=Wz]
} |\HYq`!g%7
|aAu4
_:RQ9x'
public void setSSiteURL(String value) 3o).8b_3g
{ wEQ7=Gyx
sSiteURL = value; Kmk}Yz
} $5(_U
;N+ v x
[{s 1=c
public String getSFilePath() XsH(8-n0
{ M lv
return sFilePath; /KL;%:7
} {z^6V\O5
FWi c/7
{"^LUw8fd
public void setSFilePath(String value) WO}l&Q
{ 6[b?ckvi
sFilePath = value; '7'*+sgi$
} ^Vbx9UN/
O }ES/<an
dwH8Zg$B
public String getSFileName() R04%;p:k#
{ )+Nm@+B
return sFileName; fX:)mLnO/
} ]q,5'[=~4h
( M > C
4$5d*7
public void setSFileName(String value) ]"ZL<?3g
{ SxX2+|0g`g
sFileName = value; ^)JUl!5j]C
} xJ-(]cO'
`[OJ)tHE
Sckt gp8
public int getNSplitter() YmBo/IM
{ %=ZN2)7{
return nSplitter; Y)Os]<N1
} Q3@MRR^tY
QU#u5sX A
Moldv x=M
public void setNSplitter(int nCount) nV[0O8p2Md
{ A^m]DSFOO
nSplitter = nCount; [!g$|
} i)@IV]]6yL
} o@6hlLr
a/4!zT
B4&K2;fg_
/* tny^sG/'
**Utility.java t PJW|wo
*/ ?k|}\l[X1
package NetFox; 6\+ZTw
{vp|f~}zTw
n#US4&uT4A
public class Utility { p aQ"[w
`<?{%ja
a?d)lnk
public Utility() #4yh-D"
{ :2Fy`PPab
A^%li^qz
7_=7 ;PQ<
} 7U3b YU~;
Y ,
//线程睡眠 Mnv2tnU]
public static void sleep(int nSecond) ?<*mIf:?
{ Au=9<WB%H
try{ bG|aQ2HW
Thread.sleep(nSecond); ( !THd
} K3;lst>4
catch(Exception e) +,g"8&>
{ 7\T~KYb?
e.printStackTrace (); 8V08>M
} ?*nFz0cs^
} `R\nw)xq
0afDqvrC6
//日志 id"-eMwp
public static void log(String sMsg) TwaK>t96[
{ Jc3Z1Tt
System.err.println(sMsg); b3vPGR
} _Yms]QEZ
2!Gb4V
iC.k8r+~
public static void log(int sMsg) /A4^l]H;+3
{ eM) I%
System.err.println(sMsg); 6^Q/D7U;s
} ]zt77'J
} MB"TwtW
}5nVZ;
h,!#YG@>
/* ?x\tE]
**TestMethod.java V~~4<?=A
*/ 6F)^8s02h
package NetFox; 4H]~]?F&
:|5\XV)>
O,c}T7A'?w
public class TestMethod { er%D`VHe
cU[^[;4J<
<aPbKDF~V
public TestMethod() ~x #RIt
{ ///xx/weblogic60b2_win.exe m) -DrbE
try{ aQTISX;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [e6zCN^t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,SQ`, C _5
SiteFileFetch fileFetch = new SiteFileFetch(bean); })#SjFq<V
fileFetch.start(); kgZiyPcw
} 2x<A7l)6
catch(Exception e){e.printStackTrace ();} cN&]JS,
VUF$,F9
dU"ca|u
} s-[v[w'E
S!r,p};
|}07tUq
public static void main(String[] args) N,?4,+Hc-
{ hUo}n>Aa
new TestMethod(); )/{zTg8$?/
} mV'XH
} 9()d7Y#d/`
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