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)); 7r+g8+4
} ZI;<7tF_z
for(int i=0;i<nEndPos.length-1;i++) hd V1nS$
{ tGdf/aTjy
nEndPos = nStartPos[i+1]; ;< )~Y-
} oY~ Dg
nEndPos[nEndPos.length-1] = nFileLength; ~n')&u{
} Z4$cyL'$P
} -F"QEL#
9~rUkHD
Z|9u]xL
//启动子线程 '\fY<Q:!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %n%xR%|
for(int i=0;i<nStartPos.length;i++) PfS:AIy
{ 2jsw"aHW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9z;HsUv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X2mREt9
nStartPos,nEndPos,i); :4)Qt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qjAWeS/
fileSplitterFetch.start(); /N>e&e[35\
} [+*$\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /WV7gO&L1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >R{qESmP=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1 Q-bYJG
nEndPos = " + nFileLength); 8l?piig#
// fileSplitterFetch[nPos.length-1].start(); B<8N96fx
plu$h-$d
qzw'zV
//等待子线程结束 G!8Z~CPF
//int count = 0; v1k)hFjPK
//是否结束while循环 5m=I*.qE
boolean breakWhile = false; MC((M,3L
K'iIJA*Sn
b?4/#&z]
while(!bStop) M}_i52
{ jJ4qR:]
write_nPos(); g>d;|sK
Utility.sleep(500); HBys
breakWhile = true; LIU}a5
ki0V8]HP
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for(int i=0;i<nStartPos.length;i++) _mS!XF~`P
{ `s '#
if(!fileSplitterFetch.bDownOver) t&5%?QyM
{ 5Ft5@UF~
breakWhile = false; 5G0$
break; JxLf?ad.
} TvNY:m6.%
} >3:?)
if(breakWhile) kpbm4t
break; fl Jp4-nx
L{l6Dd43q
~A<H9Bw
//count++; xR"M*%{@0
//if(count>4) =Cv/Y%DN
// siteStop(); o]{uc,
} PN~@
S.B<pjgt
$qF0ltUQ
System.err.println("文件下载结束！"); 3ZTE<zRQ
} %dErnc$
catch(Exception e){e.printStackTrace ();} Iu~\L0R427
} -IlJ^Al4
;TcvA
P^MOx4
//获得文件长度 2#X4G~>#h
public long getFileSize() n\I#CH0V
{ "M|P+A
int nFileLength = -1; #U=X NU}k
try{ }7{t^>;D
URL url = new URL(siteInfoBean.getSSiteURL()); ~Au,#7X)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]fnnZ
httpConnection.setRequestProperty("User-Agent","NetFox"); T9 <2A1
&2-L.Xb
nFX_+4V2
int responseCode=httpConnection.getResponseCode(); 4RKW
if(responseCode>=400) PUQES(&
{ 4GG>!@|
processErrorCode(responseCode); C=uZ1xg*,
return -2; //-2 represent access is error _46X%k
} 2;L|y._`w
!$A37j6
n/QF2&X7)
String sHeader; #jpoHvth
oIGrA-T}
~zm7?_"@]
for(int i=1;;i++) jUj<~:Q}3o
{ TGuiNobD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V~GWl1#7
//Utility.log(in.readLine()); ,=(Z00#(
sHeader=httpConnection.getHeaderFieldKey(i); xE}VTHFo'
if(sHeader!=null) hA 3HVP_
{ SUWD]k>PH
if(sHeader.equals("Content-Length")) 6#}93Dgv4
{ VZ>On$hp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RjJU4q
break; +^rh[>W
} r _,_5 @0e
} MyJ4><oG
else z|G9,:9
break; OQ :dJe6
} oRN-xng
} 9[v1h,L
catch(IOException e){e.printStackTrace ();} DPrBFmHF
catch(Exception e){e.printStackTrace ();} UH@as
{^{p,9
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Utility.log(nFileLength); jk\ dG16
y#Ht{)C
\&V0vN1
return nFileLength; c~A4gtB=
} "HD+rmUEH
sDqe(x}a
{qKxz9.y
//保存下载信息（文件指针位置） eRbGZYrJ
private void write_nPos() ^n#1<K[E
{ |eoid?=
try{ qo+N,x9o
output = new DataOutputStream(new FileOutputStream(tmpFile)); qP!eJ6[Nh"
output.writeInt(nStartPos.length); tg4Y i|5
for(int i=0;i<nStartPos.length;i++) zWw2V}U!
{ w)E@*h<Z
// output.writeLong(nPos); VS#wl|b8
output.writeLong(fileSplitterFetch.nStartPos); QYXx:nIrg
output.writeLong(fileSplitterFetch.nEndPos); I~PDaZP
} {"*VU3%q
output.close(); "`}~~.q
} p6EDQwlf
catch(IOException e){e.printStackTrace ();} +c:3o*
catch(Exception e){e.printStackTrace ();} 4A{|[}!
} d {lP
?:^mBb)T
n?#!VN3
//读取保存的下载信息（文件指针位置） Z>F^C}8f
private void read_nPos() C7T(+Wd!,
{ \u`)kJ5o1
try{ :Ud[f`t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^Yr0@pE
int nCount = input.readInt(); TAL/a*7\
nStartPos = new long[nCount]; vv6$>SU
nEndPos = new long[nCount]; [\)oo
for(int i=0;i<nStartPos.length;i++) y<W8Q<9
{ kI*(V[i
nStartPos = input.readLong(); *VSel4;\t
nEndPos = input.readLong(); 3zuF{Q2P<
} @e~]t}fH
input.close(); g*\/N,"z
} lJykyyCY+
catch(IOException e){e.printStackTrace ();} ,O=a*%0rt
catch(Exception e){e.printStackTrace ();} \8uo{#cL8
} KHKS$D
q^8EOAvnZ
~Y=@$!Uq
private void processErrorCode(int nErrorCode) XA0(f*
{ 0X..e$'
System.err.println("Error Code : " + nErrorCode); PDx)S7+w[
} 2J;`m_oP
Kj=gm .
WV;=@v
//停止文件下载 fbrp#G71y
public void siteStop() 1Wg-x0R
{ :(3|HTz
bStop = true; NX* O_/
for(int i=0;i<nStartPos.length;i++) ir>]r<Zl
fileSplitterFetch.splitterStop(); 5FvOznK^e
FHy76^h>e
pvWau1ArNq
} |YJCWFbs8
} ;SwC&.I
//负责部分文件的抓取 >Dm8m[76
**FileSplitterFetch.java ?9j{V7h
*/ &'|B =7
package NetFox; 78#!Q.##
;'T{li2
:L?_Y/K
import java.io.*; ~%w~-O2
import java.net.*; TmRxKrRs
fT:}Lj\L1
PsjbR
public class FileSplitterFetch extends Thread { ]*"s\ix
XY7Qa!>7j
Ar9nBJ`
String sURL; //File URL [um&X=1V8
long nStartPos; //File Snippet Start Position }m]q}r
long nEndPos; //File Snippet End Position 33l>{(y
int nThreadID; //Thread's ID 2H#N{>7
boolean bDownOver = false; //Downing is over H(+<)qH
boolean bStop = false; //Stop identical l'4AF| p
FileAccessI fileAccessI = null; //File Access interface D _X8-
&!.HuRiuC
iMP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0V,Nv9!S
{ yFIy`9R
this.sURL = sURL; A(6xg)_XQ
this.nStartPos = nStart; eOO+>%Z
this.nEndPos = nEnd; MlO-+}`_+
nThreadID = id; 4|J[Jdj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;~ 4k7Uz
} jjOgG-Q
jdRq6U^
;Kxbg>U
public void run() dFW=9ru+MQ
{ |qcD;
while(nStartPos < nEndPos && !bStop) %(m])
{ Id8wS!W`7
(ClhbfzD
V*n==Nb5L
try{ 5vp|?-\h>
URL url = new URL(sURL); A;K(J4y*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IFNWS,:
httpConnection.setRequestProperty("User-Agent","NetFox"); %Tcf6cK"
String sProperty = "bytes="+nStartPos+"-"; ^t.W|teD
httpConnection.setRequestProperty("RANGE",sProperty); J07O:cjyu
Utility.log(sProperty); 54p tP
%5</d5.
R|,7d:k
InputStream input = httpConnection.getInputStream(); x2wg^$F*oO
//logResponseHead(httpConnection); X33v:9=
N{akg90
HQVh+(
byte[] b = new byte[1024]; 0A$SYF$O+[
int nRead; oN2=DYC41
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) iSp
{ e=f.y<
nStartPos += fileAccessI.write(b,0,nRead); 60B-ay0e$b
//if(nThreadID == 1) nnCug
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6XUuGxQV/
} V% axeqs
4KpL>'Q=
cf8-]G?tK
Utility.log("Thread " + nThreadID + " is over!"); DQ6jT@ZDH
bDownOver = true; O&?.&h
//nPos = fileAccessI.write (b,0,nRead); =V$j6
} M-9gD[m
catch(Exception e){e.printStackTrace ();} 6vz1*\:H~
} Q|hm1q
} -e>|kPfv!
Agy <j
)^;DGzG
//打印回应的头信息 L@)&vn]
public void logResponseHead(HttpURLConnection con) <)#kq1b?
{ U{1z;lJ
for(int i=1;;i++) us{nyil1
{ hY8#b)l~lu
String header=con.getHeaderFieldKey(i); WR.x&m>
if(header!=null) bkQ3c-C<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uDG+SdyN@
Utility.log(header+" : "+con.getHeaderField(header)); )s")y
else *3Nn +T
break; rY70^<z
} 9;f|EGwZ
} :EHQ .^
Ti= 3y497S
"~$$
public void splitterStop() 1kFjas`g
{ [8]m8=n
bStop = true; X , ZeD
} |O (G nsZ
xb^Mo.\[
WcGXp$M
} `BT*,6a
{yq8<?
TbNGgjT
/* [&VxaJ("3
**FileAccess.java lizTRVBE
*//文件访问(定位，写) P^IY: -s
package NetFox; gue(C(~.k_
import java.io.*; ki4f*Ej
km>o7V&4G
ROoE%%8I
public class FileAccessI implements Serializable{ 0n5UKtB
@>O&Cpt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nlt4)
RandomAccessFile oSavedFile; YFx=b!/s
long nPos; :XS"#^aJ
Dd/}Ya(Gi
\Hum}0[
public FileAccessI() throws IOException YNM\pX'
{ q|{tQJfYg
this("",0); k>{-[X,/OV
} Z=9dMND
.cR*P<3O
60PYCqWc
public FileAccessI(String sName,long nPos) throws IOException yiT{+;g^
{ &&C~@WY,r
oSavedFile = new RandomAccessFile(sName,"rw"); "6V_/u5M;=
this.nPos = nPos; hEOJb @:R
oSavedFile.seek(nPos); $FCw$+w
} ^Kw(&v
/=M.-MU2
v MWC(m
public synchronized int write(byte[] b,int nStart,int nLen) "k>bUe|RG
{ ~&~C#yjg1
int n = -1; FOp_[rR
try{ d| \#?W&
oSavedFile.write(b,nStart,nLen); cdsQ3o
n = nLen; 9p<:LZd~
} LXxl?D
catch(IOException e) #$uZDQY_
{ P1QB`&8F
e.printStackTrace (); `Kp}s<
} s5.k|!K
XI g|G}i.
w4}(Ab<Y
return n; ~~dfpW_"
} IMR$x(g= F
nO [QcOf
nDn{zea7
} KgU[
YPQCOG
~%GSsm\J
/* * D3
**SiteInfoBean.java w{ m#Yt
*/ D[W}[r
package NetFox; 2$Y3[$
%0(>!SY
6cZ C
public class SiteInfoBean { HjPH
L4mTs-M.
hGKdGu`0
private String sSiteURL; //Site's URL .Bijc G
private String sFilePath; //Saved File's Path "b;k.Fx
private String sFileName; //Saved File's Name "2K|#,%N
private int nSplitter; //Count of Splited Downloading File V,'FlU
%>NRna
ndt8=6p
public SiteInfoBean() e)og4
{//nSplitter的缺省值为5 % NwoU%q
//default value of nSplitter is 5 Ug`
this("","","",5); %J3lK]bv(
} ?(M\:`G'
[M2Dy{dh
Ua!Odju*w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F13%)G(
{ U#l.E1Z
sSiteURL= sURL; N>T=L0`
sFilePath = sPath; 0Cv4/Ar(
sFileName = sName; 4w2L?PDMi
this.nSplitter = nSpiltter; EkV!hqs*
,DQ >&_DK
3~8AcX@
} {kv4g\a;
3g+\?L-c
s-o~@(r6
public String getSSiteURL() 2f /bEpi
{ |O^V)bZmx
return sSiteURL; pe|\'<>i
} akY6D]M
-hm9sNox
t"FRLC
public void setSSiteURL(String value) }8X:?S %
{ +0)5H>h
sSiteURL = value; {S# 5g2
} aGe\.A=
Pyit87h{
r]Z.`}Kkm
public String getSFilePath() T&e%/
{ DwQp$l'NfW
return sFilePath; |c BHBd
} 9yp^zL
Zr~"\llk
fG^7@Jw:G
public void setSFilePath(String value) I[vME"
{ @)8NI[=6O
sFilePath = value; m}sh I8S
} FxMMxY,*%
S:DcfR=a
| H5Ync[s
public String getSFileName() sVNo\
{ 3<yCe%I:
return sFileName; ggzAU6J
} P'KY.TjWb
!$4Q]@ }
9,}fx+^
public void setSFileName(String value) G;Pt|F?c
{ DB!uv[c
sFileName = value; t4*aVHT
} s"gKonwI2
4ZSfz#<[z
K4BTk!
public int getNSplitter() iFXUKGiV
{ 1/F<T
return nSplitter; &4a~6
} QLxXp
N2M?5fF
s2kGU^]y
public void setNSplitter(int nCount) #p;4:IT
{ vWZ>Hf]`L
nSplitter = nCount; _ +u sn.
} @|JPE%T
} )[F46?$vrk
\r)_-
"@F*$JGT y
/* !^rITiy
**Utility.java gt(X!iN]
*/ Ss*LgK_
package NetFox; R A-^!4tX
3g4vpKg6c
*=r@vQ
public class Utility { d{(s-
-sruxF
^*j[&:d
public Utility() j58Dki->.
{ PkZf(=-X
6T5A31 Q
{3_Ffsg`
} j@!BOL~?
c9>8IW
//线程睡眠 E0WrpGZ
public static void sleep(int nSecond) +Px<DX+
{ bs4fyb
try{ W,L>'$#pM
Thread.sleep(nSecond); U/v"?pg[
} Lk$Je O
catch(Exception e) S.?\>iH[
{ |>m# m*{S
e.printStackTrace (); !ds"88:5^
} 1VPfa
} t/EMBfLc
AOq9v~)z-
//日志 3:z4M9f
public static void log(String sMsg) U[H+87zg
{ ~50y-
System.err.println(sMsg); BdRE*9.0
} _AsHw
D:S6Mu
[7ek;d;'t
public static void log(int sMsg) C_g"omw40
{ UGezo3}
System.err.println(sMsg); H_xQ>~b
} ~Iu21Q(*
} /I`!iK
-hJ>wGI
9Le/'ovq
/* v\r7.l:hf
**TestMethod.java 8kn]_6:3i
*/ HCn]#
package NetFox; `eA&C4oFOO
u:qD*zOq
~L Bq5a
public class TestMethod { VAG+y/q
zN8&M<mTl
^`B##9g~
public TestMethod() E?;T:7.%
{ ///xx/weblogic60b2_win.exe c=U$$|qHV
try{ _g/TH-;^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); iMY0xf8l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nP3;<*T P0
SiteFileFetch fileFetch = new SiteFileFetch(bean); +X|m>9
fileFetch.start(); Wvzzjcr(j
} N4JqW
catch(Exception e){e.printStackTrace ();} Q,`2DHhK
3R$CxRc:
&xMJ^Nv
} }G:uzud10
S<bz7 k9
1Ag;s
public static void main(String[] args) ofJ]`]~VG
{ JQVw6*u{
new TestMethod(); ;JD3tM<
} Gh>fp
} ;Kd{h
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