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)); W3H+.E
} HCWNo
for(int i=0;i<nEndPos.length-1;i++) Y}s@WJ
{ ea'&xs#GK
nEndPos = nStartPos[i+1]; H[ m<RaG8
} M|,mr~rRG
nEndPos[nEndPos.length-1] = nFileLength; `=UWqb(K_
} @-HG`c ct
} -' g*^
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v&a4^s
//启动子线程 z^<L(/rg9"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bN$r k|
for(int i=0;i<nStartPos.length;i++) \$sjrqKnu
{ +Q$h ]^>~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wp)*Mbq@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lfog {Vzs
nStartPos,nEndPos,i); T4)fOu3]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nUS| sh
fileSplitterFetch.start(); !3X0FNGq
} D^Jk@<*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /FD5G7ES
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -I.d}[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1)m@?CaI`
nEndPos = " + nFileLength); TaE~s
// fileSplitterFetch[nPos.length-1].start(); lVOu)q@l7g
F$BbYf2i
V#REjsf,t-
//等待子线程结束 Zf$Np50@(
//int count = 0; qz?mh4Oh
//是否结束while循环 M(x$xAiD
boolean breakWhile = false; rf~Y6U?7
8N&+7FK
1u3,'8F
while(!bStop) L){iA-k;Ec
{ \K`L3*cBKK
write_nPos(); 5GA C`}}
Utility.sleep(500); v6.t{6zYgY
breakWhile = true; M?m,EQh.
s\!>"J bAQ
3?2 FP|G8
for(int i=0;i<nStartPos.length;i++) oND@:>QBF
{ I[)%,jd
if(!fileSplitterFetch.bDownOver) mKrh[nA
{ h2ytS^
breakWhile = false; &xRo^iV?
break; Q></`QWpoB
} L:XC
} wO?{?+I`q
if(breakWhile) "&/-N[is
break; c\a_VRN>r
'5&s=M_
8NyJc"T<.
//count++; [ ol9|sdu
//if(count>4) kuyjnSo9i
// siteStop(); jCbV,0)^
} y@0E[/O
BauU{:Sh
C8 \5A8c
System.err.println("文件下载结束！"); DL$@?.?I
} :#@= B]
catch(Exception e){e.printStackTrace ();} 7}M2bH} \K
} PDs@?nz,
$Y69@s%f
;)N>t\v
//获得文件长度 '>r7V
public long getFileSize() EoK~S\dS
{ 94B\5I}
int nFileLength = -1; hzkcP
try{ UQ{L{H
URL url = new URL(siteInfoBean.getSSiteURL()); ggJO:$?$L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *S2ypzwRZ,
httpConnection.setRequestProperty("User-Agent","NetFox"); [Xb@Wh:yG
9eH$XYy
uj :%#u
int responseCode=httpConnection.getResponseCode(); BNL;Biyt7
if(responseCode>=400) uEX!xx?Q#
{ g$b<1:8
processErrorCode(responseCode); dCRyOid$
return -2; //-2 represent access is error /~zai}
} 8F._9U-EN
&Z`#cMR{H
hCC<?5q
String sHeader; #B4%|v;`E?
T}8Y6N<\m
6i1LjLB
for(int i=1;;i++) '&\kxNglJ
{ |`.([2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 30SW\@
//Utility.log(in.readLine()); Ytl4kaYS
sHeader=httpConnection.getHeaderFieldKey(i); EOCN&_Z;
if(sHeader!=null) 6oGYnu;UZ
{ Uu`9"
if(sHeader.equals("Content-Length")) Mnscb
{ zG(\+4GE!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2nR[Xh?L
break; :Of^xj>A
} YJ\Xj56gv
} /Njd[=B
else g*_cPU0~m
break; VIv&ofyAR
} <ZNzVnVA
} RS8Hf~0G
catch(IOException e){e.printStackTrace ();} ME*LHr,
catch(Exception e){e.printStackTrace ();} >k (C
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E"5*Ei)^3
Utility.log(nFileLength); MRdduPrM%$
,%M$0poKM
mWsI}2
return nFileLength; [k/@E+;
} )r jiY%F$
2+e}*&iQpp
nCdR EXw
//保存下载信息（文件指针位置） V=o t-1,j7
private void write_nPos() h-`}L=
{ ]?!mS[X
try{ a ?)NC
output = new DataOutputStream(new FileOutputStream(tmpFile)); AJF#Aw `o
output.writeInt(nStartPos.length); 2Eu`u!jhx
for(int i=0;i<nStartPos.length;i++) uC(V
{ %-1O.Q|f
// output.writeLong(nPos); Y2~nBb
output.writeLong(fileSplitterFetch.nStartPos); gcl5jB5)>
output.writeLong(fileSplitterFetch.nEndPos); @X#F3;
} }f6HYU
output.close(); oYH^_V
} ,Ge"anO
catch(IOException e){e.printStackTrace ();} .nx2";oi
catch(Exception e){e.printStackTrace ();} ` 2V19s]
} oYm[V<nIl
nH[yJGZYSA
pSdI/Vj'=
//读取保存的下载信息（文件指针位置） H _zo1AW
private void read_nPos() D=-SO +
{ X:nN0p #
try{ "W955?4m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W*),y:
int nCount = input.readInt(); <^5Z:n!q
nStartPos = new long[nCount]; t*1fLumXR
nEndPos = new long[nCount]; 7`DBS^O]dG
for(int i=0;i<nStartPos.length;i++) $#9;)8J
{ .uMn0PE
nStartPos = input.readLong(); o<pf#tifv
nEndPos = input.readLong(); +|n*b
} JR@`2YP-
input.close(); hG12ZZD
} EVsC>rz
catch(IOException e){e.printStackTrace ();} PgF* 1
catch(Exception e){e.printStackTrace ();} Lh!J >
} YUtC.TR1
CVL3VT1j0
T[UN@^DP(
private void processErrorCode(int nErrorCode) svcK?^ HTe
{ 5YeM%%-S
System.err.println("Error Code : " + nErrorCode); I 8`VNA&b
} 3z{?_;bR
1W^taJH]
i@"@9n~
//停止文件下载 M_/7D|xl/T
public void siteStop() QI'Oz{vE
{ "K6&dk jY
bStop = true; :VRNs
for(int i=0;i<nStartPos.length;i++) 4.[^\N
fileSplitterFetch.splitterStop(); ,St#Vla
qNB<T('
7:plQ!7^
} $P^q!H4D
} S2sQOM@
//负责部分文件的抓取 N4F.Y"R$(
**FileSplitterFetch.java 6xTuNE1
*/ MyJ%`@+1
package NetFox; {?}E^5Z*g
0zmE>/O+
Z>:NPZODf
import java.io.*; Vc&!OE
import java.net.*; p6>Svcc
8lvV4yb
/Kql>$I
public class FileSplitterFetch extends Thread { ls\WXCH
=.Pw`.
S"NqM[W
String sURL; //File URL I_}SB|
long nStartPos; //File Snippet Start Position CkOz
long nEndPos; //File Snippet End Position c|e~BQdRw
int nThreadID; //Thread's ID [%y';`( x
boolean bDownOver = false; //Downing is over [1g8*j~L
boolean bStop = false; //Stop identical zy/@ WFPE
FileAccessI fileAccessI = null; //File Access interface a*lh)l<KV
pjKWtY@=X
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =Y{(%sn
{ <\rT%f}3^
this.sURL = sURL; UZ\u;/}
this.nStartPos = nStart; \A 2r]
this.nEndPos = nEnd; K[YI4pt7
nThreadID = id; kCWV r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YxYH2*q@
} >JHryS.j$4
j4gF;-m<
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public void run() `i3NG1 v0
{ q9KHmhUD
while(nStartPos < nEndPos && !bStop) fInb[
{ HVR /7&g
ry`Ho8N
x-WmMfcz&
try{ ak$f"py x
URL url = new URL(sURL); X`kk]8=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lA| 5E?
httpConnection.setRequestProperty("User-Agent","NetFox"); oK6tTK
String sProperty = "bytes="+nStartPos+"-"; ?GKb7Oj
httpConnection.setRequestProperty("RANGE",sProperty); >)fi^
Utility.log(sProperty); q/4J.jL
9UdM`v)(
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InputStream input = httpConnection.getInputStream(); EH+"~-v)ae
//logResponseHead(httpConnection); gX@HO|.t
>?2M }TV3
h5*JkRm
byte[] b = new byte[1024]; ysQ_[ ]/
int nRead; RIWxs Zt
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ugdQAg
{ vOn`/5-
nStartPos += fileAccessI.write(b,0,nRead); 6a(yp3
//if(nThreadID == 1) dI.WK@W'o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w1Nm&}V
} g0xuxK;9c
"h{q#~s
kj#?whK6~
Utility.log("Thread " + nThreadID + " is over!"); .F4>p=r
bDownOver = true; GFj{K
//nPos = fileAccessI.write (b,0,nRead); =)0,#9k U]
} }NHaCG[,
catch(Exception e){e.printStackTrace ();} hci6P>h<ia
} ? &o2st
} pA'4|ffwe
zqimR#u
cvn@/qBq*t
//打印回应的头信息 |HiE@
public void logResponseHead(HttpURLConnection con) y`Wty@
{ >:74%D0UF
for(int i=1;;i++) [owWiN4`s
{ Ci@o|Y }tP
String header=con.getHeaderFieldKey(i); MK%9:wZ
if(header!=null) ~qiJR`Jj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }*M6x;t
Utility.log(header+" : "+con.getHeaderField(header)); $t$ShT)
else y;35WtDVb
break; [<lHCQXJ/
} 5V?&8GTe
} {%rA1g
0IsPIi"7
.?8;qA
public void splitterStop() wcrCEX=I>{
{ ,;EIh}
bStop = true; :|>h7v
} G)EU_UE9
8zZvht*
3@etRd;]Kr
} \\iQEy<i
&PR5q7
rN<0 R`4sE
/* &|s0P
**FileAccess.java R6` WN
*//文件访问(定位，写) iOd&BB6
package NetFox; <wk!hTmW
import java.io.*; qmkAg }2
;,hwZZA
!y\'EW3|G
public class FileAccessI implements Serializable{ 4`4kfiS$
Tm~" IB*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \o z#l'z
RandomAccessFile oSavedFile; iFd+2S%
long nPos; TJ10s%,V
8H%;WU9-
iN bIp"W
public FileAccessI() throws IOException }5ret
{ Tr_w]'
this("",0); !{ y@od@T
} tIWmp30S
xs{3pkTYD
]N~2 .h
public FileAccessI(String sName,long nPos) throws IOException )1]ZtU
{ 2i)^!c
oSavedFile = new RandomAccessFile(sName,"rw"); G"r1+#
this.nPos = nPos; _~'=C#XI)
oSavedFile.seek(nPos); hCi60%g/n
} _zR+i]9
+Zb;Vn4
(of#(I[m7
public synchronized int write(byte[] b,int nStart,int nLen) eQ$Y0qH1E
{ !44/sr'
int n = -1; 6LvW?z(J
try{ Lm iOhx
oSavedFile.write(b,nStart,nLen); 0CZ:Bo[3
n = nLen; g{7.r-uu
} R4[N:~Z$|
catch(IOException e) oI?3<M^
{ S(k3 `;K
e.printStackTrace (); ^%d\qd`
} YX!{P=Ua
n7zm>&
B al`y
return n; r)Ma3FL0;
} |-fgj'
/fKx}}g)
5[8xV%>;
} 0CWvYC%e
6gL#C&
C(eTR1
/* {AhthR%(1
**SiteInfoBean.java U'k*_g
*/ 6]&OrS[
package NetFox; .6ylZ
x!?u^
f&=AA@jLv
public class SiteInfoBean { XPavReGf
h&M{]E9=
h}>"j%I
private String sSiteURL; //Site's URL Z&G+bdA>,
private String sFilePath; //Saved File's Path |hKDvH
private String sFileName; //Saved File's Name 7!$Q;A
private int nSplitter; //Count of Splited Downloading File y8d]9sX{
[meO[otb
;o 6lf_
public SiteInfoBean() #oS<E1
{//nSplitter的缺省值为5 ;(b9#b.
//default value of nSplitter is 5 KKb,d0T[
this("","","",5); IY_iB*T3jt
} ]P9l jwR
B |5]Jm]
kGH}[w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s%vis{2
{ zv|2:4H
sSiteURL= sURL; l^! ?@Kg,z
sFilePath = sPath; 5us:adm[pD
sFileName = sName; Z|&MKG24
this.nSplitter = nSpiltter; `vU%*g&R
V)3KS-
^\hG"5#
} \q>bs|2
DRSr%d
RaO-H
public String getSSiteURL() MOQ6:
{ |-b#9JQ[A
return sSiteURL; 4`lLf
} [xbSYu,&
Bm:98? [
3RigzT3
public void setSSiteURL(String value) 59 h]UX=
{ Ka'=o?'B5
sSiteURL = value; C0sX gM
} Vouvr<43o
g!|=%(G=
p99]
public String getSFilePath() <3oWEm
{ ?3/qz(bM
return sFilePath; Je';9(ZK
} gl~ecc
Z< 1
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public void setSFilePath(String value) Z@yW bjE7Z
{ aJSO4W)P
sFilePath = value; cA&9e<
} L s G\OG
kAKK bmE
d.[8c=$
public String getSFileName() _H9 MwJ
{ d|jNf</`
return sFileName; >;jZa
} 3(``#7
`b?R#:G
Av$]|b
public void setSFileName(String value) Vk`h2BV
{ mJ<=n?{Z
sFileName = value; zp6C3RG(
} af6M,{F
|e=,oV"
ay4 %
public int getNSplitter() \Yy$MLs
{ ['b}QW@Fx
return nSplitter; Z/G ev"p
} [Hx0`Nc K
tCw<Ip
%3s1z<;R[S
public void setNSplitter(int nCount) *}Xf!"I#]N
{ :Oy%a'w
nSplitter = nCount; f<-Jg
} pLl(iNf]
} I"xo*}
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O6@j &*jS
/* ,1hxw<sNR
**Utility.java f@6QvkIa
*/ e*sfPHt
package NetFox; HsxVZ.dS
GmK^}=frj
+|*IZ:w)
public class Utility { a a<8,;
0`Kj25
)z>|4@,
public Utility() Qo>b*Ku;
{ @<,X0S
.28<tEf
YP 6`L
} -<6\1J
} j<)L,
//线程睡眠 ~cWAl,(B<F
public static void sleep(int nSecond) %Celc#v
{ Ii6<b6-
try{ AWcLUe{
Thread.sleep(nSecond); 5sdn[Tt##
} P)"noG_'i
catch(Exception e) C^s^D:
{ {baq+
e.printStackTrace (); =NpYFKmMhV
} FW.7'7G@n
} z Eq GD2"
57aXQ8u{
//日志 K)6rY(x >
public static void log(String sMsg) m)8BgCy
{ v0ujdp,B
System.err.println(sMsg); vx\r!]
} ih)zG
$Y;U[_l#
v/@^Q1G/:
public static void log(int sMsg) ?yZ+D z\
{ -N6f1>}pE
System.err.println(sMsg); ; a/X<
} %) /s;Q,
} t9nqu!);
EJj.1/]|r
5]~'_V
/* -M~8{buxv
**TestMethod.java ,aOl_o -&
*/ _> f`!PlB|
package NetFox; a Ve'ry
>~#yu&*D
B`YTl~4
public class TestMethod { LU \i0|i|
#r$cyV!k
I?]ohG K
public TestMethod() @#<D ^"
{ ///xx/weblogic60b2_win.exe Q`~jw>x
try{ ^pxX]G]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7jxslI&F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?:pP8/y
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~Uj=^leYO
fileFetch.start(); ;m0~L=w
} :Hn6b$Vy8
catch(Exception e){e.printStackTrace ();} :uP,f<=)K
tankR9(o
[O$Wa:< 0x
} VdPtPq1
?OId\'q
O $LfuL
public static void main(String[] args) rr+|Zt Y
{ Vn7*JS
new TestMethod(); NYt&@Z}]
} Sw:7pByjI
} &[_g6OL
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