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)); h{dR)#)GF<
} hQm"K~SW=
for(int i=0;i<nEndPos.length-1;i++) (#4
{ ac/=%om8u
nEndPos = nStartPos[i+1]; (TQx3DGq
} qkCj33v
nEndPos[nEndPos.length-1] = nFileLength; Rf&~7h'+
} U~,~GU=X
} ypoJ4EZ(
,]OL[m
dy4! >zxF
//启动子线程 AWp{n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;NyX9&@
for(int i=0;i<nStartPos.length;i++) {V> >a
{ ERql^Yr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qqm7p ,j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U%swqle4
nStartPos,nEndPos,i); +m> %(?=A
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t+R8{9L-
fileSplitterFetch.start(); -Qs4s
} RJ#xq#l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \= M*x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +) pO82
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )czuJ5
nEndPos = " + nFileLength); s^ t1T&
// fileSplitterFetch[nPos.length-1].start(); ews4qP
(s/hK
'?q \mi
//等待子线程结束 SA5 g~{"
//int count = 0; _L?`C
//是否结束while循环 U!GG8;4
boolean breakWhile = false; O23dtH
e}Y|'bG
vm3B>ACJ
while(!bStop) <i~MBy. (
{ MX=mGfoa
write_nPos(); |.A#wjF9
Utility.sleep(500); a88(,:t
breakWhile = true; G0Q8"]
]Zfg~K(
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for(int i=0;i<nStartPos.length;i++) Cf-R?gn]
{ &^R0kCF`
if(!fileSplitterFetch.bDownOver) qOyg&]7
{ P= e3f(M2
breakWhile = false; =Q % F~
break; 67Z.aaXD1
} %p5%Fs`sd
} mk)F3[ke
if(breakWhile) r!qr'Ht<
break; Ig&=(Kmr
v&[Ff|>
(lDbArqy
//count++; n[jyhBf\W
//if(count>4) &ukYTDM
// siteStop(); ZDVz+L|p
} GqFDN],Wp
,tdV-9N[O
=.@{uu;
System.err.println("文件下载结束！"); t)Iu\bP
} V~V_+
catch(Exception e){e.printStackTrace ();} #q7`"E=M"
} !,rp|
,_K /e
wnaT~r@U'
//获得文件长度 aS^ 4dEJ
public long getFileSize() \tLfB[S.5
{ /{eD##vhP
int nFileLength = -1; b)+;#m
try{ DKd:tL24&
URL url = new URL(siteInfoBean.getSSiteURL()); SxC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MHs2UN
httpConnection.setRequestProperty("User-Agent","NetFox"); Ae&470
PZVh)6f"c
w1Z9@*C!
int responseCode=httpConnection.getResponseCode(); KrcL*j&^
if(responseCode>=400) +{Qk9Z
{ W^}fAcQKH
processErrorCode(responseCode); ZzU3j^
return -2; //-2 represent access is error }9w?[hXW"
} [P5+}@t
o6JCy\Bx
9,7IsT8
String sHeader; ;^waUJ\Z
y be:u
FLT4:B7
for(int i=1;;i++) !Cq2<[K#
{ !f 7CN<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -;/;dz;
//Utility.log(in.readLine()); u:~2:3B
sHeader=httpConnection.getHeaderFieldKey(i); RAw/Q$I
if(sHeader!=null) idWYpU>gC
{ ZT*RD2,
if(sHeader.equals("Content-Length")) DnbT<oEL
{ [If%+mHdU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5Jo><P a
break; /U |@sw4
} Czj]jA(0f
} fq-zgqF<
else K-%x]Fp=
break; 3lw KV
} (;RmfE'PX
} "bI'XaSv
catch(IOException e){e.printStackTrace ();} )%8;C]G;
catch(Exception e){e.printStackTrace ();} jH+ddBVA
Up:<NHJT
zGtWyXP
Utility.log(nFileLength); pLB~{5u>;-
$a^YJY^_
-6wjc rTD
return nFileLength; &L&6y()G
} nVkPYeeT
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3v~804kWB
//保存下载信息（文件指针位置） JmHEYPt0
private void write_nPos() +n]z'pijb
{ nE_g^
try{ Ce:2Tw
output = new DataOutputStream(new FileOutputStream(tmpFile)); U^ bF}4m
output.writeInt(nStartPos.length); A 9I5
for(int i=0;i<nStartPos.length;i++) @'go?E)f
{ i98>=y~
// output.writeLong(nPos); zcF`Z{&+
output.writeLong(fileSplitterFetch.nStartPos); >LvQ&fAo
output.writeLong(fileSplitterFetch.nEndPos); (o+(YV^
} vuL;P"F4&
output.close(); dMo456L
} CC?L~/gPN
catch(IOException e){e.printStackTrace ();} {s]yP_
catch(Exception e){e.printStackTrace ();} ${(c`X
} k!9LJ%Xh
}n!$)W*?
+M@,CbqD
//读取保存的下载信息（文件指针位置） "pQFIV,
private void read_nPos() ]yc&ffe%
{ |=R@nn
try{ teRK#: .P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O+8]y4%5
int nCount = input.readInt(); u"WqI[IV
nStartPos = new long[nCount]; 2n/cqK
nEndPos = new long[nCount]; 3aD\J_
for(int i=0;i<nStartPos.length;i++) ]+C;C
{ XTzz/.T;Z
nStartPos = input.readLong(); /z'fFl^6O
nEndPos = input.readLong(); *@2+$fgz
} 58TH|Rj+I
input.close(); 9j[lr${A
} {jnfe}]
catch(IOException e){e.printStackTrace ();} <oFZFlY@
catch(Exception e){e.printStackTrace ();} 33O O%rWi
} y7iHB k"^:
/UwB6s(
n U0
private void processErrorCode(int nErrorCode) S6Er#)k
{ tc.`P]R
System.err.println("Error Code : " + nErrorCode); #Uc0W
} BWtGeaW/sr
U|[+M@F_L
0a1Vj56{)
//停止文件下载 #*J+4aw3
public void siteStop() OrN~ Y#D
{ V:<NQd
bStop = true; l"T{!Oq
for(int i=0;i<nStartPos.length;i++) OI@;ffHSW
fileSplitterFetch.splitterStop(); "pa}']7#
A.f!SYV6
J5i$D0K[
} etcpto=Mo
} BQ[,(T`+R
//负责部分文件的抓取 &CtWWKS"
**FileSplitterFetch.java z}772hMB
*/ 1[? xU:;9
package NetFox; dV~d60jOF
]]R!MnU:$
@<^_ _."
import java.io.*; qD#E, "%
import java.net.*; aPELAU-
ceKR?%8s
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public class FileSplitterFetch extends Thread { p3e_:5k
n]K`ofjl^
\J)ffEKIp
String sURL; //File URL A2C|YmHk
long nStartPos; //File Snippet Start Position 0 It[Pa qG
long nEndPos; //File Snippet End Position D%WgE&wtM
int nThreadID; //Thread's ID XIS.0]~
boolean bDownOver = false; //Downing is over '4T]=s~N
boolean bStop = false; //Stop identical ,_G((oS40
FileAccessI fileAccessI = null; //File Access interface QTy xx
f@G3,u!]i
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z_gjC%(y
{ Zze(Ik
this.sURL = sURL; e9F\U
this.nStartPos = nStart; a>_Cxsb&`
this.nEndPos = nEnd; |I0O|Zdv
nThreadID = id; q?9x0L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RV%aFI )
} Ao2m"ym
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public void run() *8WcRx
{ >TnV Lx<
while(nStartPos < nEndPos && !bStop) E~b Yk6
{ (Lp$EC&%6
KS9eV
Z`W@Od$f
try{ oo+nqc`,O
URL url = new URL(sURL); eD#R4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H@j D%
httpConnection.setRequestProperty("User-Agent","NetFox"); W-72&\7
String sProperty = "bytes="+nStartPos+"-"; iC$mb~G
httpConnection.setRequestProperty("RANGE",sProperty); r+#!]wNPe
Utility.log(sProperty); Vm3e6Y,K
c:$W5j('Z
Vk3xWD~
InputStream input = httpConnection.getInputStream(); ~_;x o?@ba
//logResponseHead(httpConnection); S8zc1!
^")SU(`
bOY<C%;C
byte[] b = new byte[1024]; gG>|5R0
int nRead; A,WZ}v}_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Msk^H7
{ >3{l"SPU
nStartPos += fileAccessI.write(b,0,nRead); g_T[m*
//if(nThreadID == 1) *.+Eg$'~V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dx<KZR$!V
} yv2&K=rZp
[6$n
t9Sog~:'
Utility.log("Thread " + nThreadID + " is over!"); rX^wNH
bDownOver = true; xn=/SIS
//nPos = fileAccessI.write (b,0,nRead); 9=-d/y?
} 2X= pu.;F
catch(Exception e){e.printStackTrace ();} SccaX P
} [|:kS
} *j`{ K
@~Uu]1
qMHI-h_A
//打印回应的头信息 XAnN<
public void logResponseHead(HttpURLConnection con) #RyX}t X,
{ gGtl*9a=
for(int i=1;;i++) ]V`L\
{ 52zD!(
String header=con.getHeaderFieldKey(i); nw)yK%`;M
if(header!=null) U}=o3u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;q3"XLV(T[
Utility.log(header+" : "+con.getHeaderField(header)); P:p@Iep
else &4m\``//9
break; pyf/%9R:d
} |z5`h
} O.9r'n4f
%GY U$aA
figCeJ!W4
public void splitterStop() M?3Nh;
{ >~D-\,d|f
bStop = true; "IvFkS=*Q
} p>O>^R
| M|5Nc>W
rEM#J"wF
} $;1TP|
WZ3GI l
{hE\ECT-
/* =/|2f; Q
**FileAccess.java U^xz>:~
*//文件访问(定位，写) Jxq;Uu9
package NetFox; sXpA^pT"T
import java.io.*; 7M#irCX
$v6`5;#u
oaK&!$S]
public class FileAccessI implements Serializable{ v&8%t 7|
-9f> rH\3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a%fMf[Fu
RandomAccessFile oSavedFile; j3J\%7^i
long nPos; ;;3oWsil}
@_+B'<2
'/ >7pB
public FileAccessI() throws IOException Ag6^>xb^
{ 8,l~e8&
this("",0); !n?8'eqWru
} &F!Ct(c99
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uxKj7!(#
public FileAccessI(String sName,long nPos) throws IOException 9A-=T>|of
{ ISbhC!59
oSavedFile = new RandomAccessFile(sName,"rw"); '0\v[f{K3G
this.nPos = nPos; ,f]GOH
oSavedFile.seek(nPos); &rj)Oh2
} Zdm7As]
lV*dQwa?i
'H]&$AZ;@
public synchronized int write(byte[] b,int nStart,int nLen) j\uh]8N3<
{ q\`0'Z,
int n = -1; >7[o=!^:4
try{ Vzs_g]V
oSavedFile.write(b,nStart,nLen); j&c YRKpz
n = nLen; DC5^k[m
} RAh4#8]
catch(IOException e) whoQA}X>
{ @C?.)#
e.printStackTrace (); OX r%b
} *?-,=%,z/
k'(eQ5R3L
i.(kX`~J1
return n; -fB;pS,
} DC-tBbQkk
!I8m(axW
T- |36Os4
} 8(b C.
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qSg=[7XOO
/* 4dgo*9
**SiteInfoBean.java aYBc)LCd
*/ T|L_+(M{
package NetFox; 9r efv
k\NwH?ppu
mbS`+)1=l
public class SiteInfoBean { q9^6A90
JJ+A+sfdk
y;r{0lTB
private String sSiteURL; //Site's URL `> :^c
private String sFilePath; //Saved File's Path \D<w:\P
private String sFileName; //Saved File's Name a St
private int nSplitter; //Count of Splited Downloading File ]c=nkS
"3r7/>xy
PE\.JU
public SiteInfoBean() ,ezC}V0M
{//nSplitter的缺省值为5 RM(MCle}
//default value of nSplitter is 5 \a}_=O
this("","","",5); U=G}@Y
} ?C6DK{S(
^Fe%1Lnt
b)e';M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e0nr dM[i
{ )^)j=xs
sSiteURL= sURL; *2(W`m
sFilePath = sPath; ,2R7AHk
sFileName = sName; TB@0j ;g
this.nSplitter = nSpiltter; Ul`~d !3zH
P#ro;3S3y
qIC9L"I
} ;GjZvo
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public String getSSiteURL() 8=Z]?D=
{ 6M/*]jLq4
return sSiteURL; '20SoVp
} @_L:W1[
wyVQV8+&>
A;'*>NS
public void setSSiteURL(String value) &W|r P(
{ 6iZ:0y0t+6
sSiteURL = value; ,e{|[k
} ))<1"7D^^
kYl')L6
NF0=t}e
public String getSFilePath() 7F;dLd'
{ ~*-%tFSv
return sFilePath; VGPBD-6)
} "8%z,lHw
@8;0p
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public void setSFilePath(String value) n_qDg
{ d${RZ}/
sFilePath = value; IcDAl~uG
} 4NN81~v 4
2^TJ_xG~
Z ^w5x:
public String getSFileName() xwm-)~L4T
{ HfN:oww
return sFileName; "\:ZH[j
} Y unY'xY
?#cX_
Bv)4YU
public void setSFileName(String value) w2mLL?P
{ F[65)"^
sFileName = value; [HV9KAoA
} a BHV
j+E[[
LM~,`#3Ru
public int getNSplitter() pH'1be{K
{ G.}Ex!8R7_
return nSplitter; _s&sA2r<
} c[DC
-nvK*rn>}
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public void setNSplitter(int nCount) [p%OIqC`pB
{ lZq`,E_L
nSplitter = nCount; >h+G$&8[y
} 02EbmP
} -A\J:2a|
+EnJyli
,XZ[L? >
/* BUozpqN}
**Utility.java YnCWmlC
*/ 7T)J{:+0!|
package NetFox; pKM5<1J
w,CZ*/^
CLU[')H0
public class Utility { ,iUYsY
}: W6Bo-|
0tzMu#
public Utility() x!<?/I)X
{ nKoc%TNqe
d_5wMK6O6
6-'Y*
} g@ ZZcBx
'x-PQQ
//线程睡眠 1HBdIWhHv.
public static void sleep(int nSecond) xzGs%01]
{ I2b\[d
try{ e?&4;
Thread.sleep(nSecond); l*l(QvN_
} =}12S:Qhj
catch(Exception e) TAbC-T.EV
{ bN#)F
e.printStackTrace (); I'_.U]An
} (S@H'G"
} r}gp{Pf7e
t-vH\m
//日志 & q(D90w.
public static void log(String sMsg) lIN`1vX(
{ zqq$PaH*
System.err.println(sMsg); xV h-Mx+M
} [}/\W`C
S"Q$ Ol"
nsq7,%5
public static void log(int sMsg) y?|JBf
{ ={a8=E!;
System.err.println(sMsg); 8-HMKD#V
} k($N_XlE
} /}]Irj4m
} r#by%P
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/* 0 w"&9+kV
**TestMethod.java 4YVxRZ1[3
*/ ya9V+/i7T_
package NetFox; |!\(eLR9>
YdI|xu>0A^
UeVRd
public class TestMethod { P2nb&lVdu
!2('Cq_^
~D4%7U"dv
public TestMethod() 0!n6tz lT
{ ///xx/weblogic60b2_win.exe T/V 5pYl
try{ kpkN GQ2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mn=G6h T}W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (i,TxjS'od
SiteFileFetch fileFetch = new SiteFileFetch(bean); FS%Xq-c
fileFetch.start(); 0<+=Ew5Z
} crJyk#_
catch(Exception e){e.printStackTrace ();} OG_2k3v
zl: 5_u=T
1or4s{bmo
} B_k[N}|zD
!9l c6W
=$B:i>z<
public static void main(String[] args) -P09u82
{ =NH p%|
new TestMethod(); 0ih=<@1K
} o)P'H"Ki
} Y9TaU]7]
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