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)); !h7:rv/
} *qSvSY*
for(int i=0;i<nEndPos.length-1;i++) zx=eqN@!@
{ F)Q[ cai
nEndPos = nStartPos[i+1]; !]g[u3O
} U+B"$yBR
nEndPos[nEndPos.length-1] = nFileLength; 1) 2-UT
} V )oXJL
} f['lY1#V1
6c-'CW
=lk'[P/p`
//启动子线程 $A{$$8P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f:~G)
for(int i=0;i<nStartPos.length;i++) <|Lz#iV37
{ [u K,.G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UV}:3c6ZX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :M{ )&{D
nStartPos,nEndPos,i); HP[B%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {-me;ayk
fileSplitterFetch.start(); @^YXE,
} cRr3!<EZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K3 BWj33
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x zF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YB4 ZI
nEndPos = " + nFileLength); OQ_<Vxz
// fileSplitterFetch[nPos.length-1].start(); W?4:sLC#3
Y#V(CIDe
x+6z9{O
//等待子线程结束 'h6G"=+
//int count = 0; O^-QqCZE
//是否结束while循环 gTTKjlI[
boolean breakWhile = false; R,PN?aj
sgK =eBE
t/O^7)%
while(!bStop) ?;P6#ByR
{ pn(i18x
write_nPos(); ]3*w3Y!XK
Utility.sleep(500); vW*Mf}=
breakWhile = true; RPeH[M^
v*GS>S
dZ(Z]`L,B
for(int i=0;i<nStartPos.length;i++) )hO%W|
{ k}<H
if(!fileSplitterFetch.bDownOver) l}^ziY!
{ =#9#unvE!
breakWhile = false; qG 20
break; }#e=*8F7
} j1{`}\e
} }6%\/d1~ 6
if(breakWhile) t-C|x)J+
break; ]Bf1p
>E4,zs@7t
|iBf6smF
//count++; CT|0KB&
//if(count>4) UQh.o
// siteStop(); 8h|}Q_
} sRcd{)|Cq
y,&[OrCm^\
&4WA/'>R
System.err.println("文件下载结束！"); }15&<s
} ~$4(|Fq/
catch(Exception e){e.printStackTrace ();} UYZC% $5x
} UIf#Gy|l
(NR( )2
`&fW<5-
//获得文件长度 =d5;F`m
public long getFileSize() >T[Y>]
{ `fEzE\\!*
int nFileLength = -1; [|*7"Q(
try{ u?SwGXi~8
URL url = new URL(siteInfoBean.getSSiteURL()); cOpe6H6,bz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tk'&-v'h
httpConnection.setRequestProperty("User-Agent","NetFox"); wVf 7<@/y
mk~CE
MhE".ZRd
int responseCode=httpConnection.getResponseCode(); 7oIHp_Zq
if(responseCode>=400) "u~` ZV(
{ H*<E5^#dw
processErrorCode(responseCode); ke W7pN?
return -2; //-2 represent access is error r>bgCQ#-n
} O!dS;p-F
}+/Vk
xh#_K@8
String sHeader; Jg'#IM
6 .?0 {2s
9$X" D
for(int i=1;;i++) 0$Mxu7 /
{ Sb2_&5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T^7}Qs9
//Utility.log(in.readLine()); 'Bt!X^
sHeader=httpConnection.getHeaderFieldKey(i); Gy["_;+xU
if(sHeader!=null) .c<U5/
{ R1Rk00Ow:
if(sHeader.equals("Content-Length")) _/P;`@
{ F)eP55C6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =m (u=|N3
break; 0k\,z(e
} CHqi5Z/+
} ak:f4dEd
else b9?Vpu`?
break; 5GJkvZtFY
} ='kCY}dkO
} o(54 A['
catch(IOException e){e.printStackTrace ();} n>Oze7hVY
catch(Exception e){e.printStackTrace ();} 1 <T|
%|JL=E}%|
V:5aq.o!
Utility.log(nFileLength); m$_l{|4z
*tpS6{4=#7
A9ld9R
return nFileLength; 9{SzE /[
} c1_Zi
n'pJl
ON!Fk:-
//保存下载信息（文件指针位置） @ kv~2m
private void write_nPos() 0;`FS/[(f
{ %UooZO
try{ # 7dvT=
output = new DataOutputStream(new FileOutputStream(tmpFile)); wt@TR~a
output.writeInt(nStartPos.length); IR2Qc6+{
for(int i=0;i<nStartPos.length;i++) @0H0!9'
{ @m`H~]AU
// output.writeLong(nPos); V{>;Z vj1R
output.writeLong(fileSplitterFetch.nStartPos); wS7Vo{#@\
output.writeLong(fileSplitterFetch.nEndPos); -3d`e2^&}
} :si&A;k
output.close(); ^oq|^O
} L?8OWLjRy
catch(IOException e){e.printStackTrace ();} DTi^* Wj
catch(Exception e){e.printStackTrace ();} vYLspZ;S
} w0sy@OF
C.uv0
_M;{}!Gc&A
//读取保存的下载信息（文件指针位置） ca0vN^Ji
private void read_nPos() ^a3 (QKS
{ W95q1f#7
try{ 7}c[GC)F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %O[1yZh \
int nCount = input.readInt(); FoYs<aER
nStartPos = new long[nCount]; %t9Kc9u3p
nEndPos = new long[nCount]; +",`Mb
for(int i=0;i<nStartPos.length;i++) 16z WmJH
{ 9"B;o
nStartPos = input.readLong(); U~7{q >
nEndPos = input.readLong(); lQ[JA[
} K'"s9b8
input.close(); Mjl,/-0 w
} 6+s&%io4
catch(IOException e){e.printStackTrace ();} $j(4FyH\
catch(Exception e){e.printStackTrace ();} X9" T(`
} 'f %oL/,
^pfM/LQ@
8"ZcKxDk
private void processErrorCode(int nErrorCode) oz3!%'
{ f::^zAV
System.err.println("Error Code : " + nErrorCode); T2|<YJ=
} $'#}f?
:=q9ay
@\-*aS_8>
//停止文件下载 MScUrW!TA
public void siteStop() v33[Rk'
{ Fo ,8"m
bStop = true; `-W4/7
for(int i=0;i<nStartPos.length;i++) NFur+zwv
fileSplitterFetch.splitterStop(); Vj)"?|V
BTA2['
<X1[j9Qtv0
} %.uN|o&n
} I;$tBgOWq
//负责部分文件的抓取 !+UXu]kA
**FileSplitterFetch.java eIPk$j{e
*/ x<d ew
package NetFox; ~7\`qH
)kKeA
3%x-^.
import java.io.*; 9]{Ss$W3x
import java.net.*; t[b(erO'
B(-F|q\
fl_a@QdB#
public class FileSplitterFetch extends Thread { 'P&r^V\~(/
J04R,B
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String sURL; //File URL :2{ [f+
long nStartPos; //File Snippet Start Position >Ij#+=
long nEndPos; //File Snippet End Position l,b_' m@
int nThreadID; //Thread's ID qX[C%
boolean bDownOver = false; //Downing is over +$^[r
boolean bStop = false; //Stop identical [R~@#I P!
FileAccessI fileAccessI = null; //File Access interface D2:ShyYAS
k5)IBO
G6"4JTWO
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ydzvjp=
{ cf_X=;yaqy
this.sURL = sURL; qNkX:|j
this.nStartPos = nStart; yW_goS0
this.nEndPos = nEnd; %Si3LQf
nThreadID = id; N,cj[6;T%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z>'hNj)ju
} MB.LHIo
MY&?*pV)
V5I xZn%
public void run() \]L ha
{ ,#.^2O9-^
while(nStartPos < nEndPos && !bStop) 3ZYrNul"
{ rN {5^+w
`zcpaE.@
&#]||T-
try{ 34vH+,!u
URL url = new URL(sURL); -r{]9v2j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yv5c0G.D
httpConnection.setRequestProperty("User-Agent","NetFox"); {JcMJZ3
String sProperty = "bytes="+nStartPos+"-"; @Z~0!VY
httpConnection.setRequestProperty("RANGE",sProperty); Ti5"a<R4m6
Utility.log(sProperty); 3SOrM
x C>>K6Nb
)q%DRLD'G
InputStream input = httpConnection.getInputStream(); @hOY&
//logResponseHead(httpConnection); hN1{?PQ
j0e1CSE
K5d>{c
byte[] b = new byte[1024]; xkz`is77Y@
int nRead; q +c~Bd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o6:p2W
{ `+WQ^dP@
nStartPos += fileAccessI.write(b,0,nRead); 4wwRNu*
//if(nThreadID == 1) PF;`mdi-,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !=+hU/e
} ?eR^\-e
`&A-m8X
S3/Z]?o
Utility.log("Thread " + nThreadID + " is over!"); EPeV1$
bDownOver = true; }Ot2; T
//nPos = fileAccessI.write (b,0,nRead); 54&&=NVs|
} gO!:WD
catch(Exception e){e.printStackTrace ();} *wz62p
} #!M;4~Sfx
} HG})VPBa
mz .uK2l{
ob=IaZ@?
//打印回应的头信息 9KZLlEk5O
public void logResponseHead(HttpURLConnection con) g*:f#u5
{ e&="5.ik
for(int i=1;;i++) Pexg"328
{ )G9,5[
String header=con.getHeaderFieldKey(i); Ob7F39):N
if(header!=null) 7ZpU -':
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ep\a
Utility.log(header+" : "+con.getHeaderField(header)); "V7&@3
else as@I0e((
break; ).>O6A4:C
} ,N5-(W
} N7qSbiRf<
lV<j?I~?Q
R&s\h"=*
public void splitterStop() I!,FxOM|$
{ 9xUAfU
bStop = true; Sc$]ar]S
} nSV OS6
PF/eQZ*4
25`6V>\
} (K->5rSU
^<'=]?xr
=wX(a
/* W-@}q}A
**FileAccess.java l8ZzKb-
*//文件访问(定位，写) &]HY:
package NetFox; 62%=%XD
import java.io.*; #s^~'2^%4
v`pIovn
@Vac!A??:
public class FileAccessI implements Serializable{ skn];%[v\
2=xjgK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ycve[31BDd
RandomAccessFile oSavedFile; *b]$lj
long nPos; go$zi5{h#
SdBo sB3v>
Q+'QJ7fw'|
public FileAccessI() throws IOException ,v+~vXO&\
{ _kT$/k
this("",0); E h>qUa
} k9?fE
2_lb+@[W
ey>V^Fj
public FileAccessI(String sName,long nPos) throws IOException } ^67HtNQ
{ 8DP] C9
oSavedFile = new RandomAccessFile(sName,"rw"); =7uxzg/%Tj
this.nPos = nPos; D^9r#&
oSavedFile.seek(nPos); Y5Jrkr)k
} -*Z;EA-
ht%:e?@i
%JC-%TRWK
public synchronized int write(byte[] b,int nStart,int nLen) 7 xm>+(
{ c:MP^PWc
int n = -1; IH1 fvW e
try{ H$i4OQ2
oSavedFile.write(b,nStart,nLen); U6@j=|q
n = nLen; #^fDKM
} `-L{J0xq
catch(IOException e) VCZ.{MD
{ 0WI3m2i
e.printStackTrace (); RZV6\j
} {\+!@?
R3SAt-IE
kG>d^K
return n; ^ LTKX`p
} \-B8`ah
J2W:Q
R4Vi*H
} {m/h3hjFa
]N+(SU
WM_wkvYl
/* ,KHebv!
**SiteInfoBean.java \]eB(&nq
*/ OZ6gu$ n*
package NetFox; -mlBr63Bj
.Bu?=+O~
({}JvSn1
public class SiteInfoBean { eS/4gM7%
fH/J8<
-W5ml @
private String sSiteURL; //Site's URL k_;+z
private String sFilePath; //Saved File's Path xu _:
private String sFileName; //Saved File's Name X)^kJ`
private int nSplitter; //Count of Splited Downloading File #sK:q&/G`
l|c#
`}YCUm[SI
public SiteInfoBean() *uq;O*s
{//nSplitter的缺省值为5 O%.c%)4Xo
//default value of nSplitter is 5 pLvvv#Y
this("","","",5); `|\z#Et
} ;LM,<QJ
7LM?<lp]
HH+$rrTT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h`0'27\C
{ ySLa4DQf
sSiteURL= sURL; :eIu<_,}
sFilePath = sPath; %\5d?;
sFileName = sName; {uQp$`
this.nSplitter = nSpiltter; i,DnXgmz@
k<098F
}&Gt&Hm>K
} 9b8ZOk'9_
#R<ErX)F
478gl o
public String getSSiteURL() ]YP J.[n
{ O|opNr
return sSiteURL; M7|k"izv
} i1"4ztZ
Vu3;U
M~Tx4_t
public void setSSiteURL(String value) t<Iy`r71
{ F|t3%dpj
sSiteURL = value; }6;v`1Hr
} Z9MT, "
f,ajo
IXaF(2>
public String getSFilePath() MY]Z@
{ a&3pPfC
return sFilePath; dVh* a
} h7iI=[_V
%. =B=*
'$@bTW
public void setSFilePath(String value) #Ont1>T,G
{ bnb:4?d]
sFilePath = value; DdY89R 6
} /~?'zr
~|_s2T
0:Ow$
public String getSFileName() `@$qy&AJ
{ +=v6*%y"V
return sFileName; )*=ds,
} .</`#
3]=j!_yJf
|;XkU`G
public void setSFileName(String value) 9"5J-a'
{ 3dlL?+Y#
sFileName = value; z@Klj qN
} RqV* O}Am
osS?SuQTE
MlDWK_y_&
public int getNSplitter() W+v7OSd92
{ PyOj{WX>W
return nSplitter; jA&ZO>4
} ^W&qTSjh
U}w,$ Y
jF5Y-CX
public void setNSplitter(int nCount) 5%+M:B
{ v{/z`J!JR
nSplitter = nCount; f@3?kM(
} o5NV4=
} yfq Vx$YL
%r1NRg8
Y[=X b
/* -@6R`m=>
**Utility.java m&o6j>C
*/ xc4g`Xi
package NetFox; _$g2;X >
(!^i6z0Sp
4<j)1i=A
public class Utility { !fwMkws
!^~ ^D<
n};:*N! v
public Utility() 7Nu.2qE
{ /$w,8pV=
,".1![b
|ia#Elavo
} nY]5pOF:
wZ&l6J4L
//线程睡眠 WOw( -
public static void sleep(int nSecond) )Z.v fc
{ 3sh}(
try{ 2P`Z>_
Thread.sleep(nSecond); :5YL!D/&
} DZ-2Z@{PX
catch(Exception e) [;?CO<
{ aYJTSgW
e.printStackTrace (); ku8C#%.m3
} I&m C
} ~AqFLv/%
[&Yrnkgr
//日志 IE^xk@
public static void log(String sMsg) 'AU:[eyUV
{ %5?Zjp+9
System.err.println(sMsg); "s$$M\)T
} thT2U8%T
8h,>f#)0c
r |H 1Yy
public static void log(int sMsg) ;rH<
{ xaPaK-
System.err.println(sMsg); LqZsH0C
} `>i8$q%
} @N tiT,3k
%<^IAMkp
QPc4bg\J~t
/* ZOAHM1ci
**TestMethod.java &nKb<o
*/ <"GgqyRzv
package NetFox; WQJnWe
?M<q95pL
3PLYC}Jq
public class TestMethod { PVCFh$pnw
0*=[1tdWY
yi29+T7j4S
public TestMethod() UrMEL;@g
{ ///xx/weblogic60b2_win.exe n+'gVEBA
try{ Em<B9S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b.N$eJlQ&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f/?uosS
SiteFileFetch fileFetch = new SiteFileFetch(bean); #YiphR&
fileFetch.start(); 5YZh e4R
} MWl2;qi
catch(Exception e){e.printStackTrace ();} )z".lw
%X5p\VS\7
;4MC/Q/
} ^MXW,xqb
y#B4m`9
~x-"?K
public static void main(String[] args) D&dh>Pe1;
{ <n;9IU
new TestMethod(); !l(O$T9T
} "mtEjK5
} rk E;OU
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