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)); IL2e6b
} /G{&[X<4U
for(int i=0;i<nEndPos.length-1;i++) +{S Maq
{ $]nVr(OZ_
nEndPos = nStartPos[i+1]; IN<:P
} F9v)R#u~
nEndPos[nEndPos.length-1] = nFileLength; :a=ro2NH
} 4+-5,t7
} )nJzSN=>$
=jsx(3V
VtD@&N
//启动子线程 }!eF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zoR,RBU6
for(int i=0;i<nStartPos.length;i++) KSF5)CZ5
{ &qNP?>C!=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b=V)?"e-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _RN/7\
nStartPos,nEndPos,i); h_AJI\{"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z`^ K%P=
fileSplitterFetch.start(); .L~fFns/
} 6{cybD`Ef&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H<v c\r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x&QNP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (qNco8QKu3
nEndPos = " + nFileLength); %j~9O~-
// fileSplitterFetch[nPos.length-1].start(); N5[_a/
I[tAT[ <
9`OG
//等待子线程结束 7yo|ie@S
//int count = 0; C}x4#bNK
//是否结束while循环 2q2p=H>&
boolean breakWhile = false; (3)C_Z
L+v8E/W
/E=h{|
while(!bStop) U;x99Go:
{ j4.Qvj >:4
write_nPos(); >:3xi{
Utility.sleep(500); gn-=##fT:i
breakWhile = true; \DG( 8l
4U}.Skzq
U'JP1\
for(int i=0;i<nStartPos.length;i++) s4\SX,
{ 6|Ba
if(!fileSplitterFetch.bDownOver) #R~">g:w
{ Z\ "Kd
breakWhile = false; TKj/6Jz|
break; 7AZ5%o
} 'US:Mr3
} |NphG|
if(breakWhile) |HKHN?)
break; eY0Ly7
r< d?
fJSV)\e0
//count++; &-EyM*:u!
//if(count>4) E9~&f^f
// siteStop(); )W_ Y3M,
} G#_(7X&
<MI$Nl
+lY\r +;
System.err.println("文件下载结束！"); g7E`;&f
} Jgi{7J
catch(Exception e){e.printStackTrace ();} MY0[Oq cm=
} V^/h;/!^
HQ-N!pf9
vZ1D3ytfG
//获得文件长度 HnH2u;
public long getFileSize() J.CZR[XF#
{ ThT.iD[
int nFileLength = -1; RPScP
try{ Gc3PN
URL url = new URL(siteInfoBean.getSSiteURL()); YQfZiz}Fv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /_ hfjCE
httpConnection.setRequestProperty("User-Agent","NetFox"); YV2pERl
]ci|$@V
8&`T<ECq>
int responseCode=httpConnection.getResponseCode(); n]6w)wE(
if(responseCode>=400) 1*eWvYo1
{ MO(5-R`
processErrorCode(responseCode); 6w .iEb
return -2; //-2 represent access is error do:RPZ!
} XH_qA[=c]
`qYc#_ELv
ej??j<]
String sHeader; ni02N3R
*(XgUJq+
U`vt/#j 1
for(int i=1;;i++) pqNoL* H
{ y+~Aw"J}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \C'I l w
//Utility.log(in.readLine()); 'KN!m| z
sHeader=httpConnection.getHeaderFieldKey(i); )Sh;UW
if(sHeader!=null) ;Vtpq3
{ ~jrU#<'G9
if(sHeader.equals("Content-Length")) 8)2u@sx%
{ R.n`R|NOd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b^|,9en
break; Q=9VuTE
} dsft=t8s
} s*A|9uf5
else u{y5'cJ{
break; 'rcsK
} lf7H8k,-
} W1M/Z[h6)5
catch(IOException e){e.printStackTrace ();} ^dp[Z,[1z
catch(Exception e){e.printStackTrace ();} c+ H)1Dfq
Zq6ebj
rt4|GVa
Utility.log(nFileLength); NIcNL(]
?)ZLxLV::
9#A{C!75(y
return nFileLength; PeR<FSF ,i
} xdSj+507
UW~tS
boHm1hPKS
//保存下载信息（文件指针位置） d`rDEa
private void write_nPos() m0K2p~
{ i=+<7]Q
try{ "Mu$3w
output = new DataOutputStream(new FileOutputStream(tmpFile)); U*#E aL
output.writeInt(nStartPos.length); "q#g/T
for(int i=0;i<nStartPos.length;i++) ~s^6Q#Z9|
{ 1 bx^Pt)
// output.writeLong(nPos); v,O&UrZ
output.writeLong(fileSplitterFetch.nStartPos); mm~o%1|WR
output.writeLong(fileSplitterFetch.nEndPos); d(cYtM,P
} _O'rZ5}&
output.close(); ;?[+vf")
} W!Os ci
catch(IOException e){e.printStackTrace ();} [ZpG+VAJ8
catch(Exception e){e.printStackTrace ();} gbi~!S-
} +vY`?k`
'Rf#1ls#
pPqbD}p
//读取保存的下载信息（文件指针位置） 3R96;d;
private void read_nPos() j-\^ }K.&
{ Pn){xfqDl
try{ 2tTV5,(1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TEy.zzt
int nCount = input.readInt(); *v-xC5L1\
nStartPos = new long[nCount]; K0bmU(Xxp
nEndPos = new long[nCount]; F;l<>|vG
for(int i=0;i<nStartPos.length;i++) k{$"-3ed
{ -cC(d$y
nStartPos = input.readLong(); Y@xeyMzE
nEndPos = input.readLong(); xH.q
} M>l+[U
input.close(); ]$%4;o4O
} D+nj[8y
catch(IOException e){e.printStackTrace ();} {ca^yHgGy
catch(Exception e){e.printStackTrace ();} 9S`b7U=P
} rb4g<f|
Wam?(!{mOf
]uXsl0'`V
private void processErrorCode(int nErrorCode) :re(khZq#
{ @g` ,'r
System.err.println("Error Code : " + nErrorCode); "PP0PL^5F
} I ywx1ac
gG?*Fi
o*S $j Cf?
//停止文件下载 ]qTr4`.
public void siteStop() Tm,L?Jh
{ $6+P&"8
bStop = true; 8-#2?=
for(int i=0;i<nStartPos.length;i++) |I<-x)joIK
fileSplitterFetch.splitterStop(); ^d=@RTyo/
FK('E3PG
+ {dIs
} QxL FN(d
} !S}Au Mw
//负责部分文件的抓取 qf{B
**FileSplitterFetch.java =5#Jsn?U
*/ '.v^seU
package NetFox; 3`!KndY1
Lu5.$b
)}lV41u
import java.io.*; 'Z9F0l"Nr
import java.net.*; =&xoyF
~n\ea:.
VAzJclB
public class FileSplitterFetch extends Thread { 2C&%UZim;P
Q*(C)/QW
!Z)^c&
String sURL; //File URL {NDe9V5
long nStartPos; //File Snippet Start Position J4X35H=Z
long nEndPos; //File Snippet End Position Ku'U^=bVm:
int nThreadID; //Thread's ID ?5gpk1
boolean bDownOver = false; //Downing is over YtQWArX,
boolean bStop = false; //Stop identical 2J;CiEB
FileAccessI fileAccessI = null; //File Access interface MPc=cLv
~(S4/d5
p$<qT^]&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vRs5-T
{ ?^Ux+mVE
this.sURL = sURL; -qF|Y f
this.nStartPos = nStart; g{(nt5|^l
this.nEndPos = nEnd; 9mm(?O~'p
nThreadID = id; z$b!J$A1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _XPc0r:?>
} bq]a8tSB
9\2&6H
>S]')O$c
public void run() q"oNB-bz
{ [t'"4
while(nStartPos < nEndPos && !bStop) Awh)@iTL
{ r1]e:
RdHR[Usm
qiN'Tuw9
try{ 7m:,-xp
URL url = new URL(sURL); iI7~9SCE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AJu.
httpConnection.setRequestProperty("User-Agent","NetFox"); IgL8u
String sProperty = "bytes="+nStartPos+"-"; sn%fE
httpConnection.setRequestProperty("RANGE",sProperty); nc)`ISI
Utility.log(sProperty); :Ib\v88WIv
Is[0ri
<5%We(3
InputStream input = httpConnection.getInputStream(); f -5ZXpWs'
//logResponseHead(httpConnection); 3}+ \&[
dGe
1wt]J!hgV
byte[] b = new byte[1024]; rB]/N,R
int nRead; r^)<Jy0|r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ";]m]PRAam
{ \ :.p8`
nStartPos += fileAccessI.write(b,0,nRead); /_\4(vvf
//if(nThreadID == 1) }=gGs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oLoa71Q}
} 8z"Yo7no
?$Pj[O^hl
LJD"N#c
Utility.log("Thread " + nThreadID + " is over!"); q`hg@uwA{`
bDownOver = true; b%(0AL
//nPos = fileAccessI.write (b,0,nRead); 1Jt%I'C?
} Nsq%b?#
catch(Exception e){e.printStackTrace ();} 2ip~qZNw><
} {$^|^n5j
} mwxJ#
~gN'";1i
k>"I!&#g
//打印回应的头信息 $)3/N&GXR
public void logResponseHead(HttpURLConnection con) Dp8(L ]6
{ <,{v>vlw
for(int i=1;;i++) |dK-r
{ |@RO&F
String header=con.getHeaderFieldKey(i); y3#\mBiw
if(header!=null) >qCT#TY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <IYt*vlm
Utility.log(header+" : "+con.getHeaderField(header)); LHps2,
else ?k#%AM
break; PA E)3
} \xt!b^d0
} 7j+.H/2
ee0J;pP2#
jVDNThm+
public void splitterStop() VaB7)r
{ j[9B,C4
bStop = true; eMs`t)rQ
} (H$eXW7
[7bY(
aUnm9ur
} ,#crtX
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q9OIw1xQr*
/* (/%}a`2#o
**FileAccess.java , Le_PJY)
*//文件访问(定位，写) hm&~6rB
package NetFox; KksbhN{AB
import java.io.*; )YZ41K5N
1yhx)m;f
'@$?A>.cj
public class FileAccessI implements Serializable{ q+K`+& @\
nP}/#Wy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8w{V[@QLn
RandomAccessFile oSavedFile; ?}W:DGudZ
long nPos; ?f%@8%px
+/ #J]v-
z >pq<}R6
public FileAccessI() throws IOException toF@@%
{ b^v.FK46G
this("",0); U<*dDE~z
} kr3ZqMfeI
^0r@",
}RD,JgmV
public FileAccessI(String sName,long nPos) throws IOException O".#B
{ C ZJW`c/
oSavedFile = new RandomAccessFile(sName,"rw"); R8ZW1
this.nPos = nPos; =14pEe
oSavedFile.seek(nPos); *bR _ C"-
} V482V#BP
.9`.\v6R
(j2]:BVu
public synchronized int write(byte[] b,int nStart,int nLen) *{XbC\j
{ L:~ "Vw6]_
int n = -1; W{k}ogI;
try{ -`rz[";n
oSavedFile.write(b,nStart,nLen); 0n5N-b?G-@
n = nLen; k&9 b&-=fk
} zg)]:
catch(IOException e) Zu5`-[mw
{ d=q2Or
e.printStackTrace (); XrYz[h*)!
} ^G5_d"Gr
p`Ax)L\f
K !`tEW[
return n; *r[PZ{D+
} {AJspLcG
kGCd!$fsk
4SmhtC
} ny{|{a
q4Q1Ib-<2
uQrD}%GI
/* E{h
**SiteInfoBean.java mlX^5h'
*/ zxXm9zrLo
package NetFox; gR%fv
]5B5J
l\a 0 k4
public class SiteInfoBean { Fj|C+;Q.
9=Y-w s
qY0p)`3!%
private String sSiteURL; //Site's URL =ejkE; %L
private String sFilePath; //Saved File's Path /z`LB
private String sFileName; //Saved File's Name Q R;Xj3]v
private int nSplitter; //Count of Splited Downloading File Wcw$ Zv
:4/RB%)"
7@5}WNr
public SiteInfoBean() EC|t4u3
{//nSplitter的缺省值为5 +wr2TT~
//default value of nSplitter is 5 zJOL\J'
this("","","",5); |I6\_K.=L
} ^ola5wD
=rGjOb3+
g7rn|<6FI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hgLwxJu
{ i_Ab0vye
sSiteURL= sURL; rOEk%kJ
sFilePath = sPath; #zyEN+
sFileName = sName; +\2{{~_z
this.nSplitter = nSpiltter; ZXh6Se4o
??Q'| r
ZG"_M@S.
} O'*KNJX
.k|8nNj
QJ\ o"c
public String getSSiteURL() :>c33X}
{ 4[v %]g`
return sSiteURL; 3o5aB1
} uzr(gFd
Vf:/Kokq
]nY,%XE
public void setSSiteURL(String value) 9@/X;zO
{ [W;iR_7T5
sSiteURL = value; tN&4t xB
} pX `BDYg.
_8P0iC8Zg#
aEM2xrhy,
public String getSFilePath() P>j^w#$n
{ 6 GqR]KD
return sFilePath; y@Z@ eK3
} xp7`[.
c@>Tzk%?"
FL*qV"r^n
public void setSFilePath(String value) XEl-5-M"
{ ;89 `!V O
sFilePath = value; T)?:q
} h fZY5+Z<
|WwC@3)
gqJSz}'
public String getSFileName() H0r@dn
{ I7,5ID4pn
return sFileName; F,5~a_GP?
} 3}~.#`QeY
wrI66R}@
uj;tmK>;
public void setSFileName(String value) iq*]CF
{ "NWILZwEV
sFileName = value; d5jZ?
} *oZ]k`-!8
.^ djt
&8$Gyu
public int getNSplitter() A{X:p3$eN
{ blyU53g
return nSplitter; 0P i+ (X
} [}:;B$,
pZHx
>J(._K
public void setNSplitter(int nCount) F#Y9 @E
{ $r+_Y/
nSplitter = nCount; 4:wVT;?a
} v_^>*Vm*
} U1nObA
C)Ep}eHjf_
;&7dX^oH
/* *WMI<w~_
**Utility.java bji5X')~#
*/ qHVZsZ
package NetFox; Sq22]
,6VY S\a3
iF,%^95=
public class Utility { TP3KT)
BV;dV6`z
4Ys\<\~d
public Utility() tBUn KPT
{ %vn"tp
KEfN!6
Uzh#zeZ`<
} Z;/QB6|%
Y]!WPJ`f2
//线程睡眠 zD^*->`p
public static void sleep(int nSecond) Aq5CF`e{
{ D*=.;Rq
try{ yK+1C68A
Thread.sleep(nSecond); eYtP396C|
} <cm(QNdcC
catch(Exception e) GY`mF1b
{ /tdRUX
e.printStackTrace (); (}B3df
} E)>.2{]C>
} okm }%#|
O}s Mqh
//日志 P*6h$T
public static void log(String sMsg) B<$(Nb5<
{ ~#MXhhqB
System.err.println(sMsg); b I"+b\K
} ^iA_<@[`X[
R1C}S
_w}l,
public static void log(int sMsg) >;Ag7Ex
{ \^oI3K0`
System.err.println(sMsg); <#nt?Xn
} s,CN<`/>x
} x`:c0y9uG
PQj'D<G
eQqnPqi-
/* v`r![QpYf
**TestMethod.java -#Bk
*/ u_HCXpP!Q
package NetFox; *3iEO>
+-r ~-bs
ctOBV
public class TestMethod { F,8?du]
rSa=NpFxLu
gWD46+A){
public TestMethod() AXpg_JC
{ ///xx/weblogic60b2_win.exe .QU]
try{ x?7z15\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ni$;"RGC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &K*Kr=9N
SiteFileFetch fileFetch = new SiteFileFetch(bean); \/s0p
fileFetch.start(); NR3h|'eC
} `O0bba=:=
catch(Exception e){e.printStackTrace ();} i&TWIl8
cY^'Cj
b($9gre>mI
} QQ,V35Vp[
+mPVI
5pU/X.lc
public static void main(String[] args) 6e>P!bo
{ j=dGNi)R
new TestMethod(); x,NV{uG$n
} 4_P6P
} "F=ta
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