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)); _R;+}1G/
} M5l*D'GE]
for(int i=0;i<nEndPos.length-1;i++) Yd$64d7,h
{ !Nno@SP@
nEndPos = nStartPos[i+1]; uH8`ipX
} UdX aC= Q
nEndPos[nEndPos.length-1] = nFileLength; `*Jw[Bnh8
} E']Gh
} i ,g<y
6|{uZNz
ATf{;S}
//启动子线程 W'<cAg?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0:k ~lz
for(int i=0;i<nStartPos.length;i++) *,p16"Q;
{ fn'N^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }{@RO./)[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O:(%m
nStartPos,nEndPos,i); QLAyX*%B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qYR+qSAJP
fileSplitterFetch.start(); p$&6E\#7
} .@;,'Xw1~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >jBnNA@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .X(ocs$}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", da53XEF&
nEndPos = " + nFileLength); ^p!bteA>
// fileSplitterFetch[nPos.length-1].start(); LdYaJh~h
/'0,cJnm
-}r(75C
//等待子线程结束 YK|Y^TU^
//int count = 0; sYY=MD
//是否结束while循环 /yj-^u\R
boolean breakWhile = false; js8\"
=Pgu?WU@
i*%2 e)
while(!bStop) 05m/iQ
{ 5s2334G
write_nPos(); A[m4do
Utility.sleep(500); IWcYa.=tZ
breakWhile = true; #]5|Qhrr+
zwKm;;v8
)04lf*ti
for(int i=0;i<nStartPos.length;i++) ^NTOZ0x~#
{ n"{oj7E0a
if(!fileSplitterFetch.bDownOver) `;R|SyrX
{ _[W`!#"
breakWhile = false; ^R4eW|H
break; g$*VA} s
} R4|<Vp<U2
} ^ok;<fJ
if(breakWhile) lYu1m
break; cnOk
l@om2|B
3f:I<S7
//count++; %.R_[.W
//if(count>4) @kKmkVhu*
// siteStop(); p=(;WnsK
} uOrvmb
N+PW,a
41TB
System.err.println("文件下载结束！"); -$4%@Z
} ^"%SHs
catch(Exception e){e.printStackTrace ();} 5Ffz^;i
} 97Qng*i
~Rcd
QWf)5S
//获得文件长度 aM9St!i
public long getFileSize() `B6{y9J6
{ 8P!dk5,,O
int nFileLength = -1; !DCJ2h%E[_
try{ b~b(Ed{r
URL url = new URL(siteInfoBean.getSSiteURL()); O`dob&C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :u{0M&
httpConnection.setRequestProperty("User-Agent","NetFox"); zux+ooU
8y!fqXm%)
GD'C^\EaZ
int responseCode=httpConnection.getResponseCode(); .VmI4V?}h
if(responseCode>=400) ZjEO$ts=@
{ Md {,@ G
processErrorCode(responseCode); G6eC.vU]j
return -2; //-2 represent access is error xM;gF2
} jl2nRo
) ZOmv
S_:(I^
String sHeader; q'2PG@
ooIMN =
>UJ&noUD#:
for(int i=1;;i++) %i%Xi+{3
{ ?/)5U}*M0T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =O)JPo&iwY
//Utility.log(in.readLine()); ok\+$+$ju
sHeader=httpConnection.getHeaderFieldKey(i); GKY:"q&h
if(sHeader!=null) _u;^w}0
{ #fGb M!3p
if(sHeader.equals("Content-Length")) 9rao&\eH
{ Ai->,<Ig]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;^DUtr ;
break; W'XMC"
} |-_5ouN.
} 45j+n.9=
else (4{49b
break; U&3*c+B4
} !icpfxOpjQ
} RC (v#G
catch(IOException e){e.printStackTrace ();} Ti3BlWQH
catch(Exception e){e.printStackTrace ();} {u.V8%8
0uU%jN$
kM3BP& 3m1
Utility.log(nFileLength); MmWJYF=
g-p OO/|
SC2C%.%l`
return nFileLength; qqzQKN
} t48(GKF
{C]M]b*F6(
4rM77Uw>
//保存下载信息（文件指针位置） 1wc -v@E
private void write_nPos() -'PpY302
{ 6eDIS|/
try{ GYO\l.%V5y
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4E |6l
output.writeInt(nStartPos.length); iY|YEi8
for(int i=0;i<nStartPos.length;i++) GoEIY
{ fSqbGoIQ
// output.writeLong(nPos); 3Gp4%UT&
output.writeLong(fileSplitterFetch.nStartPos); w ^<Y5K
output.writeLong(fileSplitterFetch.nEndPos); )i_FU~ LRq
} INbjk;k
output.close(); J82{PfQ"
} ~2H7_+.#
catch(IOException e){e.printStackTrace ();} Jl]]nOBQ/
catch(Exception e){e.printStackTrace ();} xD\Km>|i
} Q"hI!PO+
[V)sCAW
5GJ0EZ'X
//读取保存的下载信息（文件指针位置） ;2@sn+@
private void read_nPos() "]_|c\98
{ -/gS s<"
try{ mzT} C&hfP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +cV!=gDT
int nCount = input.readInt(); (J$A
nStartPos = new long[nCount]; K<]fElh-
nEndPos = new long[nCount]; T![K i
for(int i=0;i<nStartPos.length;i++) HJJ^pk&
{ xu:m~8%
nStartPos = input.readLong(); g Go
nEndPos = input.readLong(); rp'fli?0e
} 4{vd6T}V!
input.close(); \PLV]%3,
} <;6])
catch(IOException e){e.printStackTrace ();} b<F 4_WF
catch(Exception e){e.printStackTrace ();} bf74 "
} :T\WYKX3C
QhGg^h%6
GwW#Ww;Oc
private void processErrorCode(int nErrorCode) kQ#eWk J,
{ *c AoE l
System.err.println("Error Code : " + nErrorCode); `>sqP aD
} DYWC]*
4iLU "~
]JD$fS=_
//停止文件下载 R&4E7wrdP
public void siteStop() uf;q/Wr
{ Vd?v"2S(9
bStop = true; m_(hCY=Q$
for(int i=0;i<nStartPos.length;i++) i52R,hz
fileSplitterFetch.splitterStop(); yX-xVvlv@
s^oNQ}
^z^>]Qd
} r/4]b]n
} |?| u-y
//负责部分文件的抓取 Oq2H>eW`f
**FileSplitterFetch.java Iv<9})2K
*/ z;/'OJ[.
package NetFox; *SY4lqN
J7\q#]?
mNeW|3a
import java.io.*; x>J3tp$2
import java.net.*; ~d8>#v=Q`
*(`.h\+
9/$P_Q:3
public class FileSplitterFetch extends Thread { zOE6;c81
{6n \532@
^97ZH)Ww
String sURL; //File URL 2Y4&Sba^Y
long nStartPos; //File Snippet Start Position 3EZwF
long nEndPos; //File Snippet End Position 6J 5)4^bk
int nThreadID; //Thread's ID [;=ky<K0E
boolean bDownOver = false; //Downing is over cLU*Tx\
boolean bStop = false; //Stop identical Q$vr`yV#=6
FileAccessI fileAccessI = null; //File Access interface 9(l'xuX
=_dd4`G&<
cP2R24th
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &JlR70gdHi
{ d*>k ]X@G
this.sURL = sURL; JKT+ q*V
this.nStartPos = nStart; ,jnRt%W
this.nEndPos = nEnd; 3kQ^f=Wd
nThreadID = id; >slN:dr0:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gkz#kiGF
} LgNNtZ&F
4:@|q:DR
B<XPu=|
public void run() 3b3cNYP
{ N1!5J(V4
while(nStartPos < nEndPos && !bStop) Z]S0AB.Z@
{ E`4=C@NN+,
jp^WsHI3
_;q-+"6L;
try{ `fkrik
URL url = new URL(sURL); ?03Zy3/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2jZ}VCzRG
httpConnection.setRequestProperty("User-Agent","NetFox"); 48g^~{T4O
String sProperty = "bytes="+nStartPos+"-"; 3=l-jGJk
httpConnection.setRequestProperty("RANGE",sProperty); B%@!\D#
Utility.log(sProperty); ]2%P``Yj
+7/*y}.U
`Y\/US70{c
InputStream input = httpConnection.getInputStream(); (<C%5xk
//logResponseHead(httpConnection); |2<f<k/UT
_~nex,;r
-NPkN%h
byte[] b = new byte[1024]; W>s'4C`
int nRead; dO4#BDn"=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) CDYx/yO
{ &8AS=v
nStartPos += fileAccessI.write(b,0,nRead); ba9<(0`
//if(nThreadID == 1) O|&TL9:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WJU NJN
} r)5\3j[P
g**%J Xo
9H}iX0O
Utility.log("Thread " + nThreadID + " is over!"); x\hn;i<
bDownOver = true; x0A%kp&w
//nPos = fileAccessI.write (b,0,nRead); ;vclAsJ
} :5K~/=6x
catch(Exception e){e.printStackTrace ();} K}=8:BaUL
} @*"<U]
} T7,Gf({
Zc3:9
N"x\YHp
//打印回应的头信息 +Q!xEfpO;
public void logResponseHead(HttpURLConnection con) #Wm@&|U
{ 3zA=q[C
for(int i=1;;i++) _{`'{u
{ d)GkXll1D
String header=con.getHeaderFieldKey(i); 4fu\3A&
if(header!=null) F}B/-".^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @j\?h$A/
Utility.log(header+" : "+con.getHeaderField(header)); fpK0MS]=b
else LB*#
break; mf;^b.mKh
} `^bvj]>l
} : 9?Cm`
X\^& nLa
p-yOiG8b}
public void splitterStop() P$6f+{
{ ?` eYWZ">
bStop = true; rxgVT4
} >uchF8)e|
6KCCbg/
jRdhLs,M9
} W#Hv~1
gKs/T'PW
a._^E/EV
/* bDZKQ&
**FileAccess.java fs3-rXoB
*//文件访问(定位，写) L=$?q/=-
package NetFox; nT@6g|!
import java.io.*; 43u PH1 )
-l40)^ E}
/_:T\`5uO
public class FileAccessI implements Serializable{ @O<@f8-
#lyM+.T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K[#v(<)
RandomAccessFile oSavedFile; Qw6KX#n
long nPos; p-i.ITRS
uzVG q!'H
I_zk'
public FileAccessI() throws IOException {+/ .5
{ !rsa4t@t
this("",0); |?2 hml
} RI5g+Du?
lC /Hib
ET,0ux9F
public FileAccessI(String sName,long nPos) throws IOException %Vw|5yA4
{ BDm88<]
oSavedFile = new RandomAccessFile(sName,"rw"); [V2omSZo
this.nPos = nPos; ~E<PtDab
oSavedFile.seek(nPos); GTp?)nh^
} ^EC)~HP@C
`bZ2x@
:tjgg]
public synchronized int write(byte[] b,int nStart,int nLen) 409x!d~it
{ _UH/}!nqB
int n = -1; d-ag
try{ un$ Z7W/
oSavedFile.write(b,nStart,nLen); T1Gp$l
n = nLen; GCP{Z]u
} [xZ/ZWb/
catch(IOException e) C-a*EG
{ aDN6MZM
e.printStackTrace (); 2,8/Cb
} *l>[`U+
;T5,T
6Q.{llO
return n; wO2V%v^bp
} r 1l/) ;
l50|` 6t
08Pt(kzNA
} -~vl+L
RjR&D?dc
C@TN5?Z
/* {[M0y*^64$
**SiteInfoBean.java o~OwE7H)A
*/ '!j #X_;
package NetFox; C=oM,[ESQ0
`2B*CMW{
QMXD9H0{
public class SiteInfoBean { DEUd[
;mf4U85
[K/O5_
private String sSiteURL; //Site's URL NCowt|#t
private String sFilePath; //Saved File's Path YVQ_tCC_!
private String sFileName; //Saved File's Name la G$v-r
private int nSplitter; //Count of Splited Downloading File YBYBOH
*3A3>Rwu
dWsT Jyx~
public SiteInfoBean() E^Q@9C<!d
{//nSplitter的缺省值为5 |eHwp
//default value of nSplitter is 5 g9yaNelDh)
this("","","",5); 0[n c7)sW
} JCcN>DtP
Hv8SYQ|
1fz*SIjG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -M7K8
{ `ir&]jh.A
sSiteURL= sURL; L# `lQ"`K
sFilePath = sPath; ,N;))3
sFileName = sName; 'i@,~[Z4
this.nSplitter = nSpiltter; >.DF"]XM
+R|U4`12
k1ipvKxp:8
} {Oy9RESqc
JP{UgcaF
5SoZ$,a<e
public String getSSiteURL() NoFs-GGGh
{ dO>k5!ge|:
return sSiteURL; <Vz<{W3t
} i0k+l
hnp`s%e,
XXa(305
public void setSSiteURL(String value) a{<p'_
{ >Y7r\
sSiteURL = value; ybo#K
} YniZ( ~^K
DRH'A!r!
=?=)s
public String getSFilePath() ^y:FjQC:
{ T?W[Z_D
return sFilePath; u~" siH
} UppBnw
xj0cgK|!
PV?]UUc'n<
public void setSFilePath(String value) m!rwG(
{ F0@Qgk]\
sFilePath = value; @@'nit
} uWUR3n
3LKB;
CD^CUbGk
public String getSFileName() c]6V"Bo}A
{ %4j&H!y-w;
return sFileName; Wm<z?.lS
} ;KZrl`
cvKV95bn
1s Br.+p
public void setSFileName(String value) D+f'*|
{ }0$mn)*k
sFileName = value; vT?Q^PTO
} . 3GnZR,L
Q(lku"U'
Yx6hA#7I
public int getNSplitter() RXBb:f
{ pJd0k"{
return nSplitter; \;-qdV_JB
} ;SfNKu
U);OR
6^Ph '
public void setNSplitter(int nCount) {]=v]O|,
{ Q4X7Iu:
nSplitter = nCount; Xad*Iulj
} HeCcF+
} XdcG0D^
x Y| yI>
x;Gz6|
/* +L0J_.5%^
**Utility.java 8)sg_JC
*/ 2A*/C7
package NetFox; G-arnu)
!(Q l)C
nB=0T`vQ
public class Utility { Y[Es
~uB'3`x
DR6]-j!FK
public Utility() )%s +?
{ ):krJ+-/y
Raefj(^V
i|%5
} N<(HPE};
/KAlK5<
//线程睡眠 ?yp0$r/
public static void sleep(int nSecond) _ENuwBYW-
{ Yj3P 7k$c
try{ Te;gVG*
Thread.sleep(nSecond); :lK4 db
} p'&*r2_ram
catch(Exception e) :7\9xH
{ h4Ia>^@
e.printStackTrace (); B20_ig:
} \OcMiuw
} H>?F8R_iq
7IW> >RBF
//日志 Y;,Hzmbs6w
public static void log(String sMsg) l)Zs-V!M^\
{ NY@"&p'Q
System.err.println(sMsg); a}>Dz 1R
} j5\$[-';
\X& C4#
u?kD)5Nk
public static void log(int sMsg) !qA8Zky_
{ |z~LzSJv
System.err.println(sMsg); khAqYu")
} NhA#bn9y?
} noC?k }M
^YKy9zkTl
Ziz=]D_
/* y? "@v.
**TestMethod.java '&by3y5w-3
*/ H0a-(
package NetFox; =Y9\DeIZ
pcH<gF(k
'S?;J ,/
public class TestMethod { J{Tq%\a3
Zhzy.u/>
,GrB'N{8e
public TestMethod() cx^{/U?9}
{ ///xx/weblogic60b2_win.exe `U{mbw,
try{ BDe]18X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #dc1pfL!y{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JDv-O&]
SiteFileFetch fileFetch = new SiteFileFetch(bean); B,_`btJh
fileFetch.start(); ''S&e
} -#?<05/C>
catch(Exception e){e.printStackTrace ();} qzK("d
xQu eE{
/APcL5:=
} aI(>]sWJ
,+._;[k
5j eO"jB
public static void main(String[] args) ]` ]g@v
{ =Ikg.jYq&F
new TestMethod(); kq-6HDR
} Km3&N
} DA"}A`HfI
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