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)); kIJ=]wU|v
} Fgw$;W
for(int i=0;i<nEndPos.length-1;i++) #Fckev4
{ jP31K{G?
nEndPos = nStartPos[i+1]; l{8t;!2t
} =l4F/?u]f@
nEndPos[nEndPos.length-1] = nFileLength; S9E<)L
} |[iEi
} ZK`x(h{p)
M!Ywjvw*)3
:a*F>S!
//启动子线程 {4B7a6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B*^8kc:)L
for(int i=0;i<nStartPos.length;i++) *qKf!&
{ q@d6P~[-gj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fiQ/ &]|5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kPYQcOK8
nStartPos,nEndPos,i); <ahcE1h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6#Bg99c
fileSplitterFetch.start(); 7 aN}lQM
} ar:qCq$\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wl{wY,u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QuBaG<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kYu"`_n}
nEndPos = " + nFileLength); E@8&#<
// fileSplitterFetch[nPos.length-1].start(); Mo&Po9
WZf}1.Mh*
| (: PX
//等待子线程结束 V]|P>>`v9p
//int count = 0; .xg, j{%(
//是否结束while循环 J72YZrc
boolean breakWhile = false; AUwIF/>F(]
iYz!:TxP
F17nWvF
while(!bStop) ZZU"Q7`^
{ +\~Mx>Cn
write_nPos(); K2ry@haN
Utility.sleep(500); oT[8Iu
breakWhile = true; r8vF I6J
r&D&xsbQ
pu5-=QN
for(int i=0;i<nStartPos.length;i++) "hXB_73)V
{ -\~D6OA
if(!fileSplitterFetch.bDownOver) zP#%ya:I
{ ;T?4=15c
breakWhile = false; pYaq1_<+
break; Xw<Nnvz6
} X5wYfN
} AE&IN.-
if(breakWhile) jl~?I*Gr
break; /]"2;e-s+
VH5Vg We
B!+`km5
//count++; yXL]uh#b
//if(count>4) PV/SzfvIq
// siteStop(); e$y VV#
} {;XO'
Z}4 `y"By
:s`\jJ
System.err.println("文件下载结束！"); ( mKuFz7
} 'hl4cHk14
catch(Exception e){e.printStackTrace ();} 1VC:o]$
} uQlQ%n%
q(I`g;MF
JJ$q*
//获得文件长度 CN, oH4IU
public long getFileSize() ?O<D&CvB
{ GV T[)jS
int nFileLength = -1; {@w!kl~8
try{ E/_I$<,_y
URL url = new URL(siteInfoBean.getSSiteURL()); P85@G 2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wc#E:GJcK
httpConnection.setRequestProperty("User-Agent","NetFox"); xf]_@T;
O#962\
Au-h#YV
int responseCode=httpConnection.getResponseCode(); >2w^dI2
if(responseCode>=400) eAD uk!Iq
{ >=Pn\"j
processErrorCode(responseCode); z<c%Xl\$%
return -2; //-2 represent access is error -@EAL:kY
} 08TeGUjJ
lmRdl>
^<VJ8jk<
String sHeader; 8A ;)5!
nW*D
nF!6
for(int i=1;;i++) b,Vg3BS
{ H${5pY_M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z>si%Npm\
//Utility.log(in.readLine()); ;mAlF>6]\
sHeader=httpConnection.getHeaderFieldKey(i); %P2l@}?a
if(sHeader!=null) :|tWKA
{ C6T?D5
if(sHeader.equals("Content-Length")) (L3Etan4RE
{ rV0X*[]J>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DZ7<-SFU
break; 2`;&Uwt
} e: aa
} Qmg2lP.)
else +-*Ww5Zti
break; GWvw<`4
} 4,]z
} ;qN;oSK
catch(IOException e){e.printStackTrace ();} (rfR:[JkC2
catch(Exception e){e.printStackTrace ();} 15X.gx
W:gpcR]>
# zbAA<f
Utility.log(nFileLength); dz>2/'
$,)PO Z
Sr#\5UDS
return nFileLength; ~Bi>T15e
} o<8('j
{)?:d6"
]~K&b96(
//保存下载信息（文件指针位置） js..k*j
private void write_nPos() bQlvb
{ ("r\3Mvs
try{ :2zga=)g
output = new DataOutputStream(new FileOutputStream(tmpFile)); o^ zrF
output.writeInt(nStartPos.length); X;&Iu{&=
for(int i=0;i<nStartPos.length;i++) }nUq=@ej
{ yCvP-?2
// output.writeLong(nPos); QHDR*tB:{
output.writeLong(fileSplitterFetch.nStartPos); [2$mo;E?
output.writeLong(fileSplitterFetch.nEndPos); v6C$Y+5~
} D>fg
output.close(); 5(=5GkE)>
} XU y[l
catch(IOException e){e.printStackTrace ();} [o"<DP6w
catch(Exception e){e.printStackTrace ();} D 0 O^=v|
} 1PB"1.wnd
J6I:UML
yiw4<]{IX
//读取保存的下载信息（文件指针位置） U EjP`
private void read_nPos() 48IrC_0j
{ @tvz9N
try{ XkPE%m_5D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $*Kr4vh
int nCount = input.readInt(); 6Hp+?mmh
nStartPos = new long[nCount]; uCr :+"C
nEndPos = new long[nCount]; (Z0_e&=*
for(int i=0;i<nStartPos.length;i++) Rb!y(&>v
{ xG(xG%J
nStartPos = input.readLong(); J%u,qF}h
nEndPos = input.readLong(); ZZn$N-
} uOO\!Hqq
input.close(); apOa E7|
} 3=Q:{
catch(IOException e){e.printStackTrace ();} "<"m}rE?Q
catch(Exception e){e.printStackTrace ();} g<N;31:c\
} xg}Q~,:
Q5^ #:uZ
.ht-*
private void processErrorCode(int nErrorCode) :sQ>oNnz
{ iF9d?9TWl
System.err.println("Error Code : " + nErrorCode); 31~nay15
} )q66^%;S
$nb.[si\
D4b-Y[/"
//停止文件下载 RA!q)/+
public void siteStop() MkL)
{ t/}NX[q
bStop = true; \BuyJskE
for(int i=0;i<nStartPos.length;i++) hrm<!uKn
fileSplitterFetch.splitterStop(); =W &Mt
o@BV&|
Q~tXT_
} Zwm/c]6`
} H %c6I
//负责部分文件的抓取 _1NK9dp:
**FileSplitterFetch.java [}YUi>NGA
*/ -OSj<m<
package NetFox; (Vr%4Z8
4EHrd;|
FJDE48Vi
import java.io.*; F#>00b{Q
import java.net.*; zGFD71=#
MoE&)~0u&
W&=OtN U!
public class FileSplitterFetch extends Thread { R0}1:1}$Sn
*68 TTBq(
~N/r;omVc
String sURL; //File URL Km;}xke6
long nStartPos; //File Snippet Start Position i1|>JM[V
long nEndPos; //File Snippet End Position :{#O
int nThreadID; //Thread's ID S~i9~jA
boolean bDownOver = false; //Downing is over [Q0V5P~Q'
boolean bStop = false; //Stop identical {u/1ph-
FileAccessI fileAccessI = null; //File Access interface P&uSh?[ ^
Rh ^(91d
0eNdKE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V2ih/mh
{ bAPMD
this.sURL = sURL; ?id) 2V0s
this.nStartPos = nStart; TIKkS*$
this.nEndPos = nEnd; uhh7Ft#H
nThreadID = id; Xj 1Oxm42
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _6nAxm&x`%
} $Lr&V~
y)fMVD"(
`*3A7y
public void run() ==OUd6e}
{ &t^*0/~
while(nStartPos < nEndPos && !bStop) Cgx:6TRS
{ V 9Qt;]mQ
dS ojq6M
8YFG*HSa
try{ ~t)cbF(UO
URL url = new URL(sURL); s/tLY/U/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C< c6Ub
httpConnection.setRequestProperty("User-Agent","NetFox"); Vr EGR$
String sProperty = "bytes="+nStartPos+"-"; (oGYnN,2
httpConnection.setRequestProperty("RANGE",sProperty); Byc;r-Q5V
Utility.log(sProperty); ]p`y
1.du#w
|9jK-F6
InputStream input = httpConnection.getInputStream(); 7|5kak>=
//logResponseHead(httpConnection); %JM$]
-D~K9u]U_
I=kqkuW
byte[] b = new byte[1024]; g8Ex$,\,
int nRead; !T,<p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |dgiW"tUm
{ g{V(WyT@
nStartPos += fileAccessI.write(b,0,nRead); 4Hz3KKu
//if(nThreadID == 1) .o/|]d`%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )/jDt dI
} K=N&kda
rRRh-%.RU
IU8zidn&
Utility.log("Thread " + nThreadID + " is over!"); $5i\D rs
bDownOver = true; ,/?J!W@m
//nPos = fileAccessI.write (b,0,nRead); &V?+Y2
} N|yA]dg[
catch(Exception e){e.printStackTrace ();} KNeVSZT
} D`p2aeI
} ArtY;.cg%
mW"e
jA1S|gV
//打印回应的头信息 SSI> +A
public void logResponseHead(HttpURLConnection con) 5;XC!Gz
{ ?ES{t4"
for(int i=1;;i++) eQ'E`S_d
{ k{f1q>gd
String header=con.getHeaderFieldKey(i); fz|*Plv
if(header!=null) "o--MBq4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +PYV-@q
Utility.log(header+" : "+con.getHeaderField(header)); zu}uW,XH-
else < dE7+w
break; 1O Ft}>1
} MEI&]qI
} s>DFAu!
C/!P&`<6
i|h{<X7[
public void splitterStop() Jj]<SWh
{ '{,JuX"n
bStop = true; dU-:#QV6
} W _[9
KYTXf+oh
"I=Lbh-`
} ):Fg {7b]n
%{ U (y#
:LuA6
/* CM~x1f*v
**FileAccess.java =&g:dX|q8
*//文件访问(定位，写) ~e|E5[-i
package NetFox; *=md!^x`
import java.io.*; rE"FN~9P
fm#7}Y
`_&vvJPn@!
public class FileAccessI implements Serializable{ 6oWFjeZ0
tv-SX=T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \`8$bpW[nS
RandomAccessFile oSavedFile; D{7sfkcJ
long nPos; Bz{"K
mb'{@
U7LCd+Z5X
public FileAccessI() throws IOException M3eSj`c3
{ 9n5uO[D
this("",0); \]FPv7!
} 'QpDx&~QP
auB+g'l
:MYLap&L&
public FileAccessI(String sName,long nPos) throws IOException g6gwNC:aF
{ KsTE)@F:
oSavedFile = new RandomAccessFile(sName,"rw"); f. h3:_r
this.nPos = nPos; "MPS&OK
oSavedFile.seek(nPos); %f\j)qw
} 4<EC50@.
6R2F,b(_
F.Bij8\
public synchronized int write(byte[] b,int nStart,int nLen) h1Y^+A_
{ eiA$) rzy
int n = -1; N+]HJ`K
try{ Zirp_[KZ%
oSavedFile.write(b,nStart,nLen); uxX 3wY;M
n = nLen; iDCQqj`
} 1n)YCSA
catch(IOException e) 1k%HGQM{
{ J6 A3Hrg
e.printStackTrace (); A)#Fyde
} jlyuu
oB<!U%BN
F)aF.'$-/
return n; -LFk7a
} )|]*"yf:E
Q{ g{
kK&AK2
} ND3|wQ`M0
bdBLfWe
Nah\4-75&
/* }?CKE<#%
**SiteInfoBean.java y?iW^>|?L=
*/ =QwT)KRB%
package NetFox; =+VDb5= TV
wF-H{C'
U]M5&R=?
public class SiteInfoBean { eV9,G8
HSACaTVK
bhKe"#m|S
private String sSiteURL; //Site's URL =+4om*
private String sFilePath; //Saved File's Path y=}o|/5"
private String sFileName; //Saved File's Name GCrsf
private int nSplitter; //Count of Splited Downloading File E,/nK
-^>7\]
F~GIfJU
public SiteInfoBean() BWkTQd<t
{//nSplitter的缺省值为5 TOx@Y$_9Q8
//default value of nSplitter is 5 `nd$6i^#W
this("","","",5); mW3IR3b
} Ibv`/8xh
ZQsVSz( 1
g]?QV2bX6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $L72%T
{ ]_m(q`_
sSiteURL= sURL; G#.q%Up
sFilePath = sPath; W#L/|K!S
sFileName = sName; `cFNO:
this.nSplitter = nSpiltter; G4EuW *~
b}ODc]3
SM.KM_%K
} xE6hE'rh.O
=BO>Bi&&
>%c>R'~h
public String getSSiteURL() B*}:YV
{ V+$fh2t
return sSiteURL; >UXNR`?
} *$Z?Owl7
H6MG5f_
5>fAO =u!Q
public void setSSiteURL(String value) 0>ce~KU
{ %vRCs]
sSiteURL = value; ugs9>`fF&
} mv#*%St5
4V'HPD>=V
O-n JuZJgX
public String getSFilePath() ,b t j6hg
{ ,3Aiz|v-
return sFilePath; ?:i,%]zxC
} ka*#O"}L8
5jsZJpk$
xks Me
public void setSFilePath(String value) sV]I]DR
{ /1b7f'
sFilePath = value; R#W=*cN
} I MG^L
U.N?cKv
v4,Dt
public String getSFileName() +.QJZo_
{ L.:8qY
return sFileName; EKEJ9Y+47H
} ]l,,en5V
^p3W}D
P[tYu:
public void setSFileName(String value) QSOG(}w
{ =X7_!vSv
sFileName = value; ^ U~QQ
} bbT$$b-
E@4/<;eKK
\;JZt[
public int getNSplitter() \jx3Fs:Q
{ ?@;#|^k9
return nSplitter; KtHkLYOCG
} Gr#WD=I-}
L2OR<3*|Av
Rx?ze(
public void setNSplitter(int nCount) ;*0?C'h=
{ PlCj<b1D:
nSplitter = nCount; &^l(RBp]0
} V)P8w#,
} <>)N$$Rx&
7mE9Zo1
[v`kqL~
/* mv^X{T
**Utility.java O&,8X-Ix
*/ _<=h#lH
package NetFox; [2E(3`-u
'xEK0~awD
%Aqf=R_^
public class Utility { +wxsAGy_j
7Gy:T47T\@
wE}Wh5
public Utility() _,/~P)
{ kP ]Up&'
'ztOl`I5V
SV>tw`2
} LgNIb
?uq`|1`
//线程睡眠 ~(^P(
public static void sleep(int nSecond) 7y'uZAF
{ e?]5q ez
try{ t@qf/1
Thread.sleep(nSecond); kXSX<b<%
} UY< PiP
catch(Exception e) SndR:{
{ t WI-
e.printStackTrace (); H$h#n~W~
} U g"W6`
} Y$=jAN
32YbBGDN!f
//日志 JXB)'d0
public static void log(String sMsg) puC91
{ p~$cwbQ!
System.err.println(sMsg); &jP1Q3
} 5'} V`?S
'#'noB;,
L'= \|r
public static void log(int sMsg) [8iY0m_Qe
{ BX >L7n
System.err.println(sMsg); MR#*/Iw~
} npdljLN
} G*CPj^O
mJSfn"b}K
Hb)FeGsd).
/* Q\$3l'W
**TestMethod.java SI}s
*/ xlI=)ak{
package NetFox; :7v'[b
jxog8E
_'=,c"
public class TestMethod { !jj`Ht)
Xh9QfT,
/I%z7f91O
public TestMethod() * ,hhX psa
{ ///xx/weblogic60b2_win.exe HlGSt$woX
try{ -o ).<&#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XiW1X6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5J5?cs-!
SiteFileFetch fileFetch = new SiteFileFetch(bean); PYkhY;*
fileFetch.start(); +9_Y0<C
} Lljn\5!r<
catch(Exception e){e.printStackTrace ();} y9:4n1fg
+?_!8N8
}p)K6!J0
} 8x{Owj:Q
vSgT36ZF
o<G 9t6~
public static void main(String[] args) qN!oN*
{ ^m>4<~/
new TestMethod(); /fI}QY1
} &LLU@|
} nS+Rbhs
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