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)); l~.ae,|7
} $C#G8Ck,
for(int i=0;i<nEndPos.length-1;i++) 8HDYA$L
{ r3*0`Rup
nEndPos = nStartPos[i+1]; A}W)La\
} q,(U8
nEndPos[nEndPos.length-1] = nFileLength; A!\g!*
} gs7h`5[es
} Dyyf%'\M
hOG9
[@(M%
//启动子线程 n=qN@u;Fi#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g1UP/hNJ\8
for(int i=0;i<nStartPos.length;i++) c 2t<WRG
{ @9Rgg9r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F jsnFX;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0Z$=2c?xT
nStartPos,nEndPos,i); ..'k+0u^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d0vn/k2I
fileSplitterFetch.start(); ~PAF2
} 2dg+R)%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F%M4i`Vh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `f?v_Ui-$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0]p! Bscaf
nEndPos = " + nFileLength); p=sLKnLmZ
// fileSplitterFetch[nPos.length-1].start(); GgwO>[T
Sc#B-4m
=:Ahg 9
//等待子线程结束 OeLM*Zi
//int count = 0; ,rc?,J1l
//是否结束while循环 Jr+~'
boolean breakWhile = false; >>22:JI`
D+.< kY.
&3~lZa;D
while(!bStop) B)>r~v]
{ : .Y
write_nPos(); [;~:',vHQf
Utility.sleep(500); 4LO4SYW7
breakWhile = true; HtY0=r
_kGJqyYV
2^RWGCEv
for(int i=0;i<nStartPos.length;i++) ;r'y/Y'?
{ E0?R,+>&4
if(!fileSplitterFetch.bDownOver) B /q/6Pp
{ t+y$i@R:
breakWhile = false; e1ts/@V
break; trlZ^K
} $v5)d J
} @/jLN
if(breakWhile) nIc:<w]
break; ?'SHt9b3|
B6 rz
"u^%~2
//count++; =ie8{j2:
//if(count>4) Lxz!>JO>
// siteStop(); qTxw5.Ai!
} K=lm9K
PY.4J4nn|
CWKN0HB
System.err.println("文件下载结束！"); ^K[WFiN}
} vfBIQfH
catch(Exception e){e.printStackTrace ();} T .#cd1b
} *XN|ZGl/
S=NP}4w,_)
wMc/Og
//获得文件长度 kHMD5Q
public long getFileSize() N!me:|Dn
{ Fs+ CY
int nFileLength = -1; pAK7V;sJ
try{ $U. >]i
URL url = new URL(siteInfoBean.getSSiteURL()); xAlyik
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cl2+,!:
httpConnection.setRequestProperty("User-Agent","NetFox"); TgC8EcLr
w2 %u;D%
fyHFfPEE
int responseCode=httpConnection.getResponseCode(); 0'm$hU}
if(responseCode>=400) 4H 4W
{ `wGP31Y.
processErrorCode(responseCode); ''.P=
return -2; //-2 represent access is error Q#gzk%jL@
} R k'5L
F6'[8f
7c.96FA
String sHeader; VKGH+j[
HV0!G-h
A8|DB@Bi
for(int i=1;;i++) X1wlOE
{ r [NI#wW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ku'OM6D<
//Utility.log(in.readLine()); Wb)>APL
sHeader=httpConnection.getHeaderFieldKey(i); /kZ{+4M
if(sHeader!=null) S<Rl?El<=
{ 'J[n}r
if(sHeader.equals("Content-Length")) rHSA5.[1P
{ ;7/ ;4Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wnf3[fV6P
break; xJcM1>cT>
} &Hl*Eg f
} yW@0Q:
else N*mm[F2+F
break; P }BU7`8
} fC4#b?Q
} }^b7x;O|
catch(IOException e){e.printStackTrace ();} 5>S=f{ghFw
catch(Exception e){e.printStackTrace ();} ng0tNifZ;
--D&a;CO}
A,H|c="
Utility.log(nFileLength); M'(4{4rC
(B/od#nU
hwD;1n
return nFileLength; 6cQ)*,Q
} 'ptD`)^(
\jR('5DcB
r0Cc0TMdj
//保存下载信息（文件指针位置） r}>q*yx:
private void write_nPos() Tr\6AN?o
{ 3AQu\4+A
try{ a ](Jc)
output = new DataOutputStream(new FileOutputStream(tmpFile)); t%k1=Ow5i
output.writeInt(nStartPos.length); .,vF%pQ
for(int i=0;i<nStartPos.length;i++) M94zlW<
{ 3QZ~t#,7ij
// output.writeLong(nPos); #&$a7L}
output.writeLong(fileSplitterFetch.nStartPos); B8G9V6KS-
output.writeLong(fileSplitterFetch.nEndPos); \gU=B|W
} s3Wjg
output.close(); 2SABu796j
} s:p6oEQ=J
catch(IOException e){e.printStackTrace ();} @nNhW
catch(Exception e){e.printStackTrace ();} M9PzA'}4W6
} f+c<|"we
M~!DQ1u
SWq5=h
//读取保存的下载信息（文件指针位置） s.uw,x
private void read_nPos() dv7IHUFf
{ l<DpcLX
try{ ?7eD<|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bP+b~!3
int nCount = input.readInt(); L_~vPp
nStartPos = new long[nCount]; hQFF%xl
nEndPos = new long[nCount]; N!=$6`d
for(int i=0;i<nStartPos.length;i++) `i"7; _HoV
{ ^q@6((O
nStartPos = input.readLong(); bMCy=5
nEndPos = input.readLong(); ^Gt9.
} 3;E,B7,mQ
input.close(); fGf C[DuY
} 8am/5o
catch(IOException e){e.printStackTrace ();} =rL^^MZp
catch(Exception e){e.printStackTrace ();} ^#0k\f>_
} P;8D|u^\*
/4xp?Lo:
v:xfGA nP
private void processErrorCode(int nErrorCode) 0hCrEM!8
{ xRiWg/Z~
System.err.println("Error Code : " + nErrorCode); .ou#BWav/
} 0*4h}t9j
"Vw;y+F}
WU:r:m+ >
//停止文件下载 ;zpSyyp@
public void siteStop() 13f@Ox$
{ iC`mj
bStop = true; s9\HjK*+
for(int i=0;i<nStartPos.length;i++) jb'AOs
fileSplitterFetch.splitterStop(); No(p:Snbo
y]YUuJ9a
tUrwg
} %=G*{mK
} 15)y]N={^
//负责部分文件的抓取 OtsW>L@ O(
**FileSplitterFetch.java "'9[c"Iz
*/ ==^9_a^
package NetFox; +`p@md2L1
QKAt%"1&
?*K{1Ghf
import java.io.*; 4\rwJD<
import java.net.*; Up*.z\|'y
MmL)CT
z{uRqAG
public class FileSplitterFetch extends Thread { YB?5s`vr9d
]hC6PKJU
1 Vq)& N
String sURL; //File URL MEled:i
long nStartPos; //File Snippet Start Position o 00(\ -eb
long nEndPos; //File Snippet End Position 3{/Y&/\"'^
int nThreadID; //Thread's ID 6 h%%?
boolean bDownOver = false; //Downing is over 8~6H\.0Q
boolean bStop = false; //Stop identical h!4jl0oX]
FileAccessI fileAccessI = null; //File Access interface s<hl>vY_'
qTV;L-
~MZEAY9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *$6dNx
{ a}#8n^2
this.sURL = sURL; D>>?8a
this.nStartPos = nStart; rd\:.
this.nEndPos = nEnd; ji] H|
nThreadID = id; &X`zk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XqxmvN
} [>#@?@x`P
l+!eC lM%
fk)5TPc^
public void run() EW}7T3g
{ tUXly|k
while(nStartPos < nEndPos && !bStop) Q.zE}ZS
{ \(g/::|
%c`P`~sp
3;t{V$
try{ 'G>gNq
URL url = new URL(sURL); (h$[g"8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z H1UAf
httpConnection.setRequestProperty("User-Agent","NetFox"); _f1~r^(/T0
String sProperty = "bytes="+nStartPos+"-"; f*tKj.P
httpConnection.setRequestProperty("RANGE",sProperty); piPx8jT`F
Utility.log(sProperty); r}%2;!T
hP$v,"$
xoQ;fVNp
InputStream input = httpConnection.getInputStream(); Pr_$%x9D
//logResponseHead(httpConnection); a|u&N:v7B
-rXo}I,VI
A6faRi703
byte[] b = new byte[1024]; SAUfA5|e
int nRead; W}0cM9 g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~REP@!\r^
{ =o? Q0
nStartPos += fileAccessI.write(b,0,nRead); mQiVTIP3[O
//if(nThreadID == 1) ]?"1FSu-8r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CA8N
} S`?L\R.:
6U!zc]>
^U@-Dp,k+
Utility.log("Thread " + nThreadID + " is over!"); A."]6R<
bDownOver = true; YZllfw$9
//nPos = fileAccessI.write (b,0,nRead); 9~Ve}NB#z&
} 3Y6W)$Q
catch(Exception e){e.printStackTrace ();} +61h!/<W
} x4 .Y&Wq#
} PrwMR_-
-s5>GwZt
2"IsNbWV
//打印回应的头信息 ~V`F5B
public void logResponseHead(HttpURLConnection con) %'vLkjI.
{ Uk0Fo(HY
for(int i=1;;i++) \]$TBN dJ4
{ $ytlj1.
String header=con.getHeaderFieldKey(i); c'Mi9,q
if(header!=null) bayDdR4T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E!SxO~
Utility.log(header+" : "+con.getHeaderField(header)); g71|t7Q
else 16Gp nb
break; 1*vt\,G
} wB0Ke
} >/eV4ma"
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y%NZ(Y,v
public void splitterStop() =T3O;i
{ p+7ZGB
bStop = true; PYPDK*Ie
} #qPWJ
V 'e_gH
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} :0o,pndU
SGK=WLGM8
azT@S=,
/* ]Ac&h aAP
**FileAccess.java GDBxciv
*//文件访问(定位，写) 3g''j7
package NetFox; $Il:Yw_
import java.io.*; ek9Y9eJ"
uL1$yf'
n)6mfoe
public class FileAccessI implements Serializable{ W^sH|2g
ZlEH3-Zv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KDUa0$"
RandomAccessFile oSavedFile; 4qe!+!#$
long nPos; lemE/(`a_
KBSO^<7
9EIOa/*
public FileAccessI() throws IOException |',$5!:0O
{ =Ti[Q5SZ
this("",0); @5Zg![G
} n k@e#
sn=_-uoU
,- FC
public FileAccessI(String sName,long nPos) throws IOException IN#Z(FMVC
{ X@cO`P
oSavedFile = new RandomAccessFile(sName,"rw"); 2F- ]0kGR|
this.nPos = nPos; ^9wQl!e ob
oSavedFile.seek(nPos); J3P)oM[
} rM5{R}+;
/_g-w93
[flx/E
public synchronized int write(byte[] b,int nStart,int nLen) ;wF 0s
{ Q xg)Wb#
int n = -1; a3?D@@Qnw
try{ 8e{S(FZ7Ed
oSavedFile.write(b,nStart,nLen); 8IrA{UU
n = nLen; mYRW/8+g
} +PfXc?VU
catch(IOException e) Wd78 bu|
{ !T3b]0z
e.printStackTrace (); c^a Dr
} @GrQ/F7
z3+7gp+I;
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return n; <f+9wuZ
} 1NI%J B
#eKg!]4-R
$V?h68[c
} 6Rcl HU
pjVF^gv,*
ICxj$b
/* ,Q>RtV
**SiteInfoBean.java K[/sVaPZ
*/ [8OQ5}do/
package NetFox; 3|qT.QR`Z
6^vseVx
Yj-JB
public class SiteInfoBean { 5:W5@e{
WPnw
ay-M.J
private String sSiteURL; //Site's URL Rz\:)<G
private String sFilePath; //Saved File's Path 8a}et8df:
private String sFileName; //Saved File's Name )CAEqP
private int nSplitter; //Count of Splited Downloading File THcK,`lX@
|'?./
Z&w/JP?
public SiteInfoBean() `<3xi9
{//nSplitter的缺省值为5 /yhGc}h
//default value of nSplitter is 5 Jq8CII
this("","","",5); $MPh\T
} tITx+i
@_ Q
+^0Q~>=VD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mb0l*'ZF
{ YrRD3P.P
sSiteURL= sURL; 7F!(60xY
sFilePath = sPath; l]wjH5mz=i
sFileName = sName; 2qQG
this.nSplitter = nSpiltter; n9p_D
S(nZ]QEG
g4"0:^/
} |)'6U3
dY6A)[dAH'
^S]-7>Yyr
public String getSSiteURL() hnf7Q l}
{ #x^dR-@
return sSiteURL; #Y9'n0 AL
} HC[)):S*
CRKuN
(}jYi*B
public void setSSiteURL(String value) ,dZ&i!@?
{ S="teH[
sSiteURL = value; `5$B"p&i
} *RpBKm&^7
/xseI)y.B
wAn}ic".b
public String getSFilePath() WhU-^`[*
{ p(J,fus
return sFilePath; (Z{&[h
} pD)$O}
ESQgN+llj
V_.n G;
public void setSFilePath(String value) <R%]9#re
{ |5(< Vk=
sFilePath = value; D6wg^'Q:
} {TV6eV
s2'] "wM
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public String getSFileName() h%0hryGB
{ D6MktE)'
return sFileName; .&Rj2d
} q)Uh_l.Cj
[`'[)B
L4wKG&
public void setSFileName(String value) p=-:Z?EW1
{ QL{{GQ_dn
sFileName = value; v\;hI5WY
} h4\j=Np
265sNaX
#^Io9dAh
public int getNSplitter() 6n}5>GSF
{ <m7T`5+
return nSplitter; WOgPhJ
} 7G^`'oZ
2:>|zmh_
xbeVqP
public void setNSplitter(int nCount) B"9/+Yj
{ 5qx,b&^w
nSplitter = nCount; AnUOv2
} Z\@m_/g
} I,pI2
r'C(+E (
hj8S#
/* '&<T;V%
**Utility.java !4ZszQg
*/ k;AV'r
package NetFox; 5m e|dvk
4jyDM68i
Le*sLuxk<
public class Utility { l-GQ AI8
@aX$}
~SWR|[
public Utility() U<|h4'(@L
{ P<1ZpL
}/{G
iTgv8
} w N-np3k
[`u3SN/P
//线程睡眠 ELlTR/NW
public static void sleep(int nSecond) GG KD8'j]
{ pjh o#yP
try{ g'F{;Ur
Thread.sleep(nSecond); ;is*[r\|1
} 13X0LN
catch(Exception e) < mb.F-8
{ s?j` _B
e.printStackTrace (); C6-71`C0
} z 5T_
} ~qk5Mk4$
~sd+ch*
//日志 D8b~-#
public static void log(String sMsg) DV,rh83.ip
{ &;D(VdSr9
System.err.println(sMsg); @n-[bN
} W)0y+H\% r
?\eq!bu
v@8=u4
public static void log(int sMsg) n<. T6
{ Ckelr
System.err.println(sMsg); 7i,Z c]
} kCq]#e~wq
} &vy/Vd
wGXnS"L!
8\85Wk{b
/* e>:bV7h j~
**TestMethod.java Ot]Y/;K
*/ 2I2#o9(Ar
package NetFox; 3e<FlH{
FzDZ<dJ
*i}Nb*Z3
public class TestMethod { D9#?l<D
r dc}e"v
Q|^TR__
public TestMethod() 7d7"^M
{ ///xx/weblogic60b2_win.exe 1b6ox6
try{ ~m]sJpW<"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /p=9"?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !+E|{Zj
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~}c`r4
fileFetch.start(); 2(, `9
} E%f;Z7G
catch(Exception e){e.printStackTrace ();} rY 0kzD/
; U)a)l'y
1lxsj{>U
} NbD"O8dL~E
.Q,IOCHk
"]jGCo>9
public static void main(String[] args) =-ky%3:`@
{ 31w9$H N
new TestMethod(); NW.<v /?=,
} cR0RJ$[d
} F^m`j6
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