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)); ^b$_I31D
} (qvH=VTwP
for(int i=0;i<nEndPos.length-1;i++) jXLd#6
{ o$eCd{HuX
nEndPos = nStartPos[i+1]; ;mT}Q;F#
} q/@+.q
nEndPos[nEndPos.length-1] = nFileLength; 3UaW+@
} ^ghYi|kQq
} qxDMDMN
"T{WOGU+
Hy1$Kvub
//启动子线程 }Nd1'BVf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >}\s-/
for(int i=0;i<nStartPos.length;i++) f;Oh"Yt
{ "[!b5f3!I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v/9DD%An
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !Ve0:$
nStartPos,nEndPos,i); w7.,ch
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1Acs0`3
fileSplitterFetch.start(); ?'Hd0)yZ
} l _%<U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1O<6=oH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g4b#U\D@)/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IdN3Ea]
nEndPos = " + nFileLength); |Y05 *!\P*
// fileSplitterFetch[nPos.length-1].start(); mvK^')
HE-5e): k
Ak,JPzT
//等待子线程结束 a#"orc j
//int count = 0; -fk;Qq3O
//是否结束while循环 rR :ZTfJs"
boolean breakWhile = false; +Wg/O -
Jw8?o/1D@
bXvO+I<
while(!bStop) `-.2Z 0
{ pB\:.?.pd
write_nPos(); r dSL
Utility.sleep(500); 8-NycG&)
breakWhile = true; ~abyjM
X!K>.r_Dg
X=KW >
for(int i=0;i<nStartPos.length;i++) ^)?Wm,{"w
{ [#mkTY
if(!fileSplitterFetch.bDownOver) N|$9v{ j_
{ ~HhB@G!3
breakWhile = false; #Zw:&' QB
break; $BMXjXd}
} :MY=Q]l
} Y|Q(JX
if(breakWhile) E`I(x&_
break; 9D+k71"+
$] "M`h
zmGHI!tP
//count++; n|)((W
//if(count>4) Hp04apM:
// siteStop(); lUB?eQuN_
} <O 0Q]`i
G(.G>8pf
)f|`mM4DW!
System.err.println("文件下载结束！"); +1YEOOfVY
} OyVP_Yx,V
catch(Exception e){e.printStackTrace ();} Lo1ySLo$G
} ;W|NG3_y
05R"/r*
myR{}G
//获得文件长度 Lm~<BBp.
public long getFileSize() ;7qIm83
{ 38p"lT
int nFileLength = -1; H^*AaA9-
try{ A6]X aF
URL url = new URL(siteInfoBean.getSSiteURL()); M,_ $s,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &{.IUg
httpConnection.setRequestProperty("User-Agent","NetFox"); Z8ea)_{#
\hgd&H0UU
P0}{xq'k9v
int responseCode=httpConnection.getResponseCode(); 9>w~B|/
if(responseCode>=400) 3\@2!:>
{ IZj`*M%3
processErrorCode(responseCode); olv?$]
return -2; //-2 represent access is error o& FOp'
} rL1yq|]I
HvG %##
'~&W'='b;
String sHeader; @6yc^DAA
;6P>S4`w
?iP7Ki
for(int i=1;;i++) Pgr2S I
{ @d0f+9d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7/IL" D
//Utility.log(in.readLine()); aE5-b ub c
sHeader=httpConnection.getHeaderFieldKey(i); kZz'&xdv'.
if(sHeader!=null) "ktuq\a@
{ I{cH$jt<
if(sHeader.equals("Content-Length")) qx5`lm~L
{ i`2SebDj'w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c%/b*nQ(=
break; \L(cFjLIl
} |qn2b=
} C7ivAh
else ]5"k%v|
break; ?d-w#<AiV
} BA:x*(%~
} ESRj<p%W
catch(IOException e){e.printStackTrace ();} &~P4yI;,
catch(Exception e){e.printStackTrace ();} #j~FlY5
}8x+F2i
NSz}
Utility.log(nFileLength); oL@-<;zKO
T<pG$4_
F)hj\aHm k
return nFileLength; \t7yH]:>@
} ][S q^5`
6XWNJb
%m |I=P
//保存下载信息（文件指针位置） ZX:rqc
private void write_nPos() }4YzP 4
{ ad: qOm
try{ .g*N+T6O
output = new DataOutputStream(new FileOutputStream(tmpFile)); jXE:aWQht
output.writeInt(nStartPos.length); B>L7UQ6_[
for(int i=0;i<nStartPos.length;i++) gUru=p
{ {1OxJn1hd
// output.writeLong(nPos); $o?U=
output.writeLong(fileSplitterFetch.nStartPos); Dm}eX:'{
output.writeLong(fileSplitterFetch.nEndPos); ^<OYW|q?\r
} \~hrS/$[$
output.close(); rpRyB9
} v;<gCzqQh
catch(IOException e){e.printStackTrace ();} 5U~KYy^v
catch(Exception e){e.printStackTrace ();} JPqd}:u3
} %, psUOY
Y.Zd_,qy
|&=-Nm
//读取保存的下载信息（文件指针位置） 2nkA%^tR
private void read_nPos() =tP9n;D
{ nv:Qd\UM
try{ T%eBgseS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JI-i7P
int nCount = input.readInt(); fwz:k]vk
nStartPos = new long[nCount]; G{} 2"/
nEndPos = new long[nCount]; bXnUz?1!d
for(int i=0;i<nStartPos.length;i++) Z&n[6aV'F
{ (&e!u{I
nStartPos = input.readLong(); D!o[Sm}JO[
nEndPos = input.readLong(); fIoc)T
} 4$KDf;m@
input.close(); H]/~ #a
} 031"D*W'i
catch(IOException e){e.printStackTrace ();} M_ukG~/
catch(Exception e){e.printStackTrace ();} q~R8<G%YK
} V8M()7uJ
Qfm$q~`D^W
^Lgvey%
private void processErrorCode(int nErrorCode) w{W+WJ
{ P5<9;PPbZ
System.err.println("Error Code : " + nErrorCode); A O:F*%Q u
} L\2"1%8Wj
H[~ D]RG}'
"#O9ij
//停止文件下载 @Ul3J )=m
public void siteStop() MQ!4"E5"j
{ epiviCYC
bStop = true; 05LkLB
for(int i=0;i<nStartPos.length;i++) n=<c_a)Nb
fileSplitterFetch.splitterStop(); K<J,n!zc
#BLHHK/[
,j*9)
} i=Qy?aU?
} WEj{2+
//负责部分文件的抓取 J 4gtm"2)
**FileSplitterFetch.java xQFY/Z
*/ {^dq7!
package NetFox; {1SsHir>
dS6 $
jKml:)k
import java.io.*; ?kO.>o
import java.net.*; n|{K_! f
=1Sny7G
E5^\]`9P
public class FileSplitterFetch extends Thread { >N|?>M*
;mU;+~YE
MR1I"gqE}I
String sURL; //File URL |E1U$,s~u
long nStartPos; //File Snippet Start Position DJ"PP5d
long nEndPos; //File Snippet End Position QOXo(S
int nThreadID; //Thread's ID 3lp'U&3`5
boolean bDownOver = false; //Downing is over Lm4`O%
boolean bStop = false; //Stop identical w.x&3aG
FileAccessI fileAccessI = null; //File Access interface +|LM"
H4y9\ -
^N/d`IAjv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r ]7: ?ir
{ wo0j/4o
this.sURL = sURL; O^MI073Q>t
this.nStartPos = nStart; 6MVu"0#
this.nEndPos = nEnd; vS8&,wJ!
nThreadID = id; 3xy2ZYw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f5V-;
} v])ew|
i{6&/TBnr
"UTW(~D'
public void run() L/ 7AGR|;C
{ @ual+=L
while(nStartPos < nEndPos && !bStop) ,4Q4{Tx
{ RzqgN*]lY
-hXKCb4YU
!.6n=r8d
try{ F{ %*(U
URL url = new URL(sURL); v.(dOIrX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sE[`x^1'8
httpConnection.setRequestProperty("User-Agent","NetFox"); a.V5fl0?I@
String sProperty = "bytes="+nStartPos+"-"; CV @P +
httpConnection.setRequestProperty("RANGE",sProperty); *tUOTA 3L
Utility.log(sProperty); 3>h2W
^bv^&V&IB
q-`&C
InputStream input = httpConnection.getInputStream(); O t)}:oG
//logResponseHead(httpConnection); &4:R(]|
M(a%Qk?]/
3mHzOs\jU
byte[] b = new byte[1024]; lOt7ij(,L
int nRead; e-rlk5k%f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J%CCUl2
{ g!XC5*}
nStartPos += fileAccessI.write(b,0,nRead); INA3^p'w
//if(nThreadID == 1) =@!t/LR7kg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;stjqTd
} hW#^H5?
-P}A26qB
t5+p]7
Utility.log("Thread " + nThreadID + " is over!"); Y1h)aQ5{
bDownOver = true; a?-&O$UHf\
//nPos = fileAccessI.write (b,0,nRead); +*8su5:[&@
} EX8+3>)
catch(Exception e){e.printStackTrace ();} C7C4 eW8
} ooVs8T2
} 9ngxkOGx
yJI~{VmU7
3=d%WPgQ
//打印回应的头信息 +4:eb)e
public void logResponseHead(HttpURLConnection con) bG]0|
{ ?y?9;;
for(int i=1;;i++) I!L J&>
{ ["D!IqI:
String header=con.getHeaderFieldKey(i); D&):2F^9.
if(header!=null) ?h[HC"V/2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {'M<dI$
Utility.log(header+" : "+con.getHeaderField(header)); -Rpra0o. C
else <[[yV
break; yUnV%@.
} UQu6JkbLL
} :(A&8<}-6
q}Q G<%VR
G!Brt&_'
public void splitterStop() 3Q$4`p;
{ vclc%ws
bStop = true; |*c1S -#
} b&P)J|Fe
JQQ[jl;
,'0#q
} v%:deaF
E<jajYj
Lng. X8D
/* GNJ/|9
**FileAccess.java ;}E}N:A
*//文件访问(定位，写) NF&Sv
package NetFox; ~LS</_N
import java.io.*; iE''>Z
RB %+|@c
F%6wdM W
public class FileAccessI implements Serializable{ o-@01_j
F-s{#V1=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y$%oR6K7-
RandomAccessFile oSavedFile; S($/Ov
long nPos; %C/p+Tg
#%[;vK
Fl_}Auj{&(
public FileAccessI() throws IOException v":q_w<k
{ \x-2qlZ
this("",0); 1%v6d !
} |<u+Xi ~
cANt7
cTq@"v di
public FileAccessI(String sName,long nPos) throws IOException 4G,FJjE`p
{ 2 q4p-
oSavedFile = new RandomAccessFile(sName,"rw"); @mCe{r*`
this.nPos = nPos; MSmr7%g3D
oSavedFile.seek(nPos); .zgh,#=
} Br!;Ac&N
HS<Jp44
)Jjp^U3Ub
public synchronized int write(byte[] b,int nStart,int nLen) ?SNacN@r
{ 8H4NNj Oy
int n = -1; +ALrHFG
try{ @/:4beh
oSavedFile.write(b,nStart,nLen); 4NID:<
n = nLen; %4nf(|8n
} )9nW`d+
catch(IOException e) I#2$CSJ
{ qj;i03 +@
e.printStackTrace (); =_`q;Tu=
} X\m\yv}}
/F;2wT;
&ww-t..
return n; xfeED^?
} W\~ie}D{
*F1TZ_GS
\}Am]Y/ w
} OWibmX
ms0V1`
}*(_JR4G
/* tM]Gu?6
**SiteInfoBean.java 0;l~B
*/ h}a}HabA
package NetFox; mFTuqujO
iF+:j8 b
?xqS#^Z
public class SiteInfoBean { !+eU
!K(
Da 7(jA+
private String sSiteURL; //Site's URL $Y7VA
private String sFilePath; //Saved File's Path :%h1Q>F
private String sFileName; //Saved File's Name 9jjeZc'
private int nSplitter; //Count of Splited Downloading File w(V%EEk
(B4)L%
j;`pAN('
public SiteInfoBean() rci,&>L"
{//nSplitter的缺省值为5 av!;k2"
//default value of nSplitter is 5 Ga5s9wC
this("","","",5); cjL)M=pIS
} *F%1~
<q=Zg7zB
D;P=\i>9-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |p/*OFC6
{ ]_(hUj._
sSiteURL= sURL; inU5eronuj
sFilePath = sPath; }W'j Dz7O
sFileName = sName; )IcSdS0@M
this.nSplitter = nSpiltter; sY!JB7!j
=Smd/'`_
J+t51B(a
} ,^G+<T6
^<!R%"o-
&lLk[/b
public String getSSiteURL() ?TpjU*Cxy
{ JxinfWk
return sSiteURL; gfK_g)'2U
} ei4LE XQ16
KfjWZ4{v
T!]rdN!
public void setSSiteURL(String value) Az@@+?,%Y
{ iz=cjmV?
sSiteURL = value; tn$TyCzckW
} 4vbGXb}!
<5G(Y#s/?
HK :K~h
public String getSFilePath() bIGcszWr
{ *{VC<<`
return sFilePath; ufk2zL8y
} .hH_1Mo8
!AXLoq$SY
oIO@#
public void setSFilePath(String value) :!s7B|_U
{ .bY>++CAPA
sFilePath = value; X`_tm3HC
} u)Kiwa
6MM\nIU)/
9_wDh0b~p
public String getSFileName() 5 <k)tF%
{ Evj%$7H1L1
return sFileName; *eHa4I
} lt-3OcC
>bWpj8Kv
?jz\[0)s
public void setSFileName(String value) |aenQA#
{ '1DY5`i{
sFileName = value; W#U|;@"
} O\f`+Q`0
4*Hzys[{
E+i(p+=4
public int getNSplitter() /TsXm-g#
{ ,ASNa^7/>
return nSplitter; $yi:0t8t
} Ub f5:
!4Zy$69R
*g*"bi*
public void setNSplitter(int nCount) m19\H
{ I)yaR+l
nSplitter = nCount; e1XKlgl
} ~zfF*A
} ASov/<D_q
~x(|'`
)SP"V~^Wn
/* W*s=No3C
**Utility.java 6p }a!
*/ _O}U4aGMTC
package NetFox; o]tfvGvU*
pf'DbY!
NV?x<LNWd
public class Utility { s@$0!8sxm
]8wm1_qV
h8O\sKn
public Utility() 9h+Hd&=
{ !pU^?Hy=
wz3X;1l`c
!GvT{
} 5\zR>Tg".
Q?T+^J
//线程睡眠 DqY"N]
public static void sleep(int nSecond) TU)Pi.Aa
{ h-Y>>l>PW0
try{ C3^3<
Thread.sleep(nSecond); /"="y'Wx
} SVwxK/Fci
catch(Exception e) esZhX)dS
{ !BW!!/U
e.printStackTrace (); msCz\8Xd
} z[ ;n2o|s
} H0tu3Pqk
hd9~Zw]V
//日志 4y}z+4
public static void log(String sMsg) %JPr 7 }
{ N/WtQSl
System.err.println(sMsg); Zs}h>$E5_B
} !nL94:8U
:RIqA/
>A]l|#Rz
public static void log(int sMsg) #t1? *4.p
{ jtfC3E,U
System.err.println(sMsg); @I1*b>X~<
} X&aQR[X
} 4J`-&05O
Ux?G:LLz
q("l?'
/* c8]%,26.
**TestMethod.java g,*fpk
*/ c)Ef]E\
package NetFox; (&)uWjq `
f#AuZ]h
cahlYv'
public class TestMethod { w<!&%
=;n>#<
$l.8
public TestMethod() S.iUiS"
{ ///xx/weblogic60b2_win.exe %#4;'\'5
try{ NR&a er
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0)PZS>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gjK: a@{
SiteFileFetch fileFetch = new SiteFileFetch(bean); Bk.`G)t
fileFetch.start(); bg9_$laDi
} S]T71W<i
catch(Exception e){e.printStackTrace ();} 2>x[_
4E!Pxjl3a
=$~x]
} +NB5Fd4
;CL^2{
*WzPxQ_
public static void main(String[] args) LM"b%
{ GQ.akA_(
new TestMethod(); Z^mIGy}
} `ALQSo~l
} 23;\l
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