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)); .2:S0=xt<
} a$P$Ngi?S
for(int i=0;i<nEndPos.length-1;i++) 8&KqrA86
{ @c#M^:9Dc
nEndPos = nStartPos[i+1]; ,O]AB
} :s'hXo
nEndPos[nEndPos.length-1] = nFileLength; ;tu2}1#r
} ?{*/VJl$
} joJ:*oL
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#^&.*'z%z
//启动子线程 {oc7Chv=/H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "jG-)k`a
for(int i=0;i<nStartPos.length;i++) (dVrGa54
{ Di8;Tq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :*{\oqFn~$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iKN800^u
nStartPos,nEndPos,i); *Me{G y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p?zh4:\F+
fileSplitterFetch.start(); 1(12`3
} f$^+;j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $*i"rlJC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -S%)2(f^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R~&i8n.
nEndPos = " + nFileLength); K~JXP5`(
// fileSplitterFetch[nPos.length-1].start(); z("Fy
!~~j&+hK\
mjz<,s`D
//等待子线程结束 nzK"eNDN.
//int count = 0; 6C|]Fm
//是否结束while循环 .JkF{&=B
boolean breakWhile = false; nmrYBw>
&,B91H*#
_z3YB
while(!bStop) ^ M4-O~
{ oPA [vY
write_nPos(); v lsS
Utility.sleep(500); kGX;x}q
breakWhile = true; hMiuv_EO!
#Qp.O@e
)c$)am\I{
for(int i=0;i<nStartPos.length;i++) @0>3))
{ -'OO6mU
if(!fileSplitterFetch.bDownOver) _ooSMp|
{ ]XH}G9X^
breakWhile = false; GI:$(<
break; )tV^)n[w
} eL+L {Ac
} ?)~j>1"S
if(breakWhile) _~ipO1*
break; D< 4!7*9%
HjFY>(e
CF`fn6
//count++; j>0~"A
//if(count>4) KQ x<{-G6
// siteStop(); rpNe8"sh
} Qb|.;_
Uieg4Iro
S}hg*mWn{$
System.err.println("文件下载结束！"); 92k}ON
} j8G>0f)
catch(Exception e){e.printStackTrace ();} '\2lWR]ndd
} FDAREE\j
jnoFNIW
B43o_H|s
//获得文件长度 "p\XaClpz
public long getFileSize() M]>JI'8
{ 79^on8k}
int nFileLength = -1; W&>+~A
try{ |7CH
URL url = new URL(siteInfoBean.getSSiteURL()); TLL.Ch|#Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a`w)awb
httpConnection.setRequestProperty("User-Agent","NetFox"); rr[9sk`^H
IpxFME%!
] 05Q4
int responseCode=httpConnection.getResponseCode(); y^C;?B<
if(responseCode>=400) ?nFT51t/4
{ B%Yb+M&K
processErrorCode(responseCode); ~P5!VNJ;r
return -2; //-2 represent access is error A&5$eGe9
} b)u9#%Q
MjI}fs<
K@{jY\AZNx
String sHeader; (D8'qx-M
f ( `.q
XEZ6%Q_
for(int i=1;;i++) 7l Aa6"Y68
{ lb1(1|#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >t8eVMMa
//Utility.log(in.readLine()); q<JI!n1O
sHeader=httpConnection.getHeaderFieldKey(i); |y%pP/;&!
if(sHeader!=null) E"Xi
{ LM _4.J
if(sHeader.equals("Content-Length")) !*%3um
{ ,)L.^<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2$NP46z}
break; /KKX;L[D(
} 2 ;B[n;Q{
} ==(M vu`
else 4r(rWlM
break; ]Wa,a T'
} ,75,~
} 9/s-|jD
catch(IOException e){e.printStackTrace ();} v;K\#uc_
catch(Exception e){e.printStackTrace ();} ur#"f'|-
&8&WY1cU
u gfV'
Utility.log(nFileLength); v!`M=0k
db%`-UST
"Ln\ZYB]
return nFileLength; `ZefSmb
} b'-gy0
_F3vC#
6 *8Ge
//保存下载信息（文件指针位置） rbtPG=t_R
private void write_nPos() ZRxB"a'
{ \O/=g6w|t}
try{ 7SqsVq`[~
output = new DataOutputStream(new FileOutputStream(tmpFile)); V u!,tpa.
output.writeInt(nStartPos.length); /|DQ_<*
for(int i=0;i<nStartPos.length;i++) jN {ED_
{ d#z67Nl6
// output.writeLong(nPos); \|&5eeE@
output.writeLong(fileSplitterFetch.nStartPos); TOuFFR
output.writeLong(fileSplitterFetch.nEndPos); zR<jZwo]#
} >$"bwr}'4B
output.close(); RZ.5:v6
} 7I.[1V`
catch(IOException e){e.printStackTrace ();} Aio0++r-
catch(Exception e){e.printStackTrace ();} d~_OWCg`
} ):[[Ch_
V?rI,'F>N
,,iQG' *
//读取保存的下载信息（文件指针位置） yi%B5KF~Al
private void read_nPos() @LmUCP~
{ ?D~uR2+Z
try{ n_+Iw,a'm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )i>KYg w
int nCount = input.readInt(); eeX>SL5'i
nStartPos = new long[nCount]; +<|w|c
nEndPos = new long[nCount]; JL$RBr
for(int i=0;i<nStartPos.length;i++) C eg6o&^
{ G dooy~cn
nStartPos = input.readLong(); @rdC/=Y[
nEndPos = input.readLong(); U--ER r8
} RcE%?2lD
input.close(); w7W-=\Hvh
} nAYjSE
catch(IOException e){e.printStackTrace ();} k{#:O=
catch(Exception e){e.printStackTrace ();} {p/m+m
} uJ$"2<O
AuCVpDH
XU54skN
private void processErrorCode(int nErrorCode) n#R!`*[
{ aG ,uF
System.err.println("Error Code : " + nErrorCode); S&0x:VW
} B?4\IXek
8,=$>@u
o]j*
//停止文件下载 $OO[C={v[
public void siteStop() t&oNJq{
{ I@B7uFj
bStop = true; D'&LwU,o
for(int i=0;i<nStartPos.length;i++) ~DD/\V
fileSplitterFetch.splitterStop(); 96BMJE'
w*}9;l
hG67%T'}A
} B?M+`;
} ?-f>zx8O
//负责部分文件的抓取 pA2U+Q@
**FileSplitterFetch.java fS~.K9
*/ U!5@$Fu
package NetFox; 0v_8YsZ!`$
A_.QHUjpx
=bDG|:+
import java.io.*; GxkG$B
import java.net.*; ,jn?s^X6Dj
cNVdGY%&
a:fHTU=\p
public class FileSplitterFetch extends Thread { ,uv$oP-
aPC!M4#
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String sURL; //File URL _x!pMj(A
long nStartPos; //File Snippet Start Position ZeeuH"A
long nEndPos; //File Snippet End Position (Ka#6
int nThreadID; //Thread's ID e-VLU;
boolean bDownOver = false; //Downing is over +6=!ve}
boolean bStop = false; //Stop identical BUb(BzC
FileAccessI fileAccessI = null; //File Access interface 0 OBkd
?@1'WD t
.H"hRYPC?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a3;.{6el)H
{ ~laZ(Bma);
this.sURL = sURL; {UcItLjY
this.nStartPos = nStart; Pio^5jhB6
this.nEndPos = nEnd; IfcFlXmt2
nThreadID = id; yShHFlO=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ju#63
} =lwS\mNs
q}5A^QX
c #kV+n<
public void run() i7rq;t<
{ M2}<gRL*}J
while(nStartPos < nEndPos && !bStop) RY{tX`
{ {rT`*P~
D@^ZpN8r
>|?T|
try{ qR qy
URL url = new URL(sURL); $J6.a!5IE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PAHlj,n)
httpConnection.setRequestProperty("User-Agent","NetFox"); Gq*)]X{Ua
String sProperty = "bytes="+nStartPos+"-"; &r%*_pX
httpConnection.setRequestProperty("RANGE",sProperty); B5:g{,C
Utility.log(sProperty); :,m)D775S
>|)0Amt
v=tj.Vg
InputStream input = httpConnection.getInputStream(); #ja`+w}
//logResponseHead(httpConnection); (x qA.(F
kA__*b}8UK
cA? x(
byte[] b = new byte[1024]; 6[.Mx}h6
int nRead; zU~..;C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /\rq$W_
{ ,:4DN&<
nStartPos += fileAccessI.write(b,0,nRead); v9U(sEDq
//if(nThreadID == 1) -vHr1I<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P]"deB|
} 5L}>+js2
jJ!-hg4?]
nKB&|!
Utility.log("Thread " + nThreadID + " is over!"); zpqGh
bDownOver = true; Cc)P5\jh
//nPos = fileAccessI.write (b,0,nRead); 8e!DDh
} A&c@8
catch(Exception e){e.printStackTrace ();} P0e""9JOo
} UMuuf6
} mSzpRa
*frJ^ Ws{
cEc,eq|
//打印回应的头信息 lVdT^"~3
public void logResponseHead(HttpURLConnection con) 3gG+`{<
{ e(~'pk"mZ
for(int i=1;;i++) SgpZ;\_
{ K)/!&{7n}a
String header=con.getHeaderFieldKey(i); |,;twj[?4
if(header!=null) >wKu6- ]a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `u#;MUg
Utility.log(header+" : "+con.getHeaderField(header)); 1xO!w+J#
else >; &s['H
break; ]eYd8s+
} .QXG"R
} j9URl$T:
X<~k =qwA
N^h|h
public void splitterStop() SqXy;S@
{ Ak5[PBbW
bStop = true; K/vxzHSl
} eC6>yD6D
m7r j>X Y
K`Bq(z?/
} VY/|WD~"CW
.4Qb5I2#
,<@,gZru
/* 4llD6&%
**FileAccess.java ]?0{(\
*//文件访问(定位，写) ;OOj[%.
package NetFox; \G$QNUU
import java.io.*; >vWEUE[
+ a-wv
SU%mmwES3
public class FileAccessI implements Serializable{ .E+OmJwD
k"">2#V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #^|| ]g/N
RandomAccessFile oSavedFile; MV:W@)rg
long nPos; f).*NX
EXA^!/)
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public FileAccessI() throws IOException JY{X,?s
{ UT3bd,,
this("",0); 9s! 2 wwh
} sYGR-:K
a9[mZVMgUK
gUl1CH&
public FileAccessI(String sName,long nPos) throws IOException bb|}'
{ Hx$.9'Oq\Q
oSavedFile = new RandomAccessFile(sName,"rw"); A-Mj|V
this.nPos = nPos; glv ;C/l
oSavedFile.seek(nPos); (tepmcf
} 'KH lrmnr
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public synchronized int write(byte[] b,int nStart,int nLen) d]U`?A,
{ R.K?
int n = -1; PPEq6}
try{ rfYP*QQY
oSavedFile.write(b,nStart,nLen); 5J ySFG3
n = nLen; Us'Cs+5XcG
} Nj+a2[
catch(IOException e) `|nH1sHFq
{ rn;<HT
e.printStackTrace (); z<!O!wX_aI
} FC{})|yh }
vd`O aM}#U
xk& NAB
return n; }3Qc 24`
} `?l3Ct*
E>E*ZZuhj
g0PT8]8
} ;`DD}j`
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OZf6/10O/
/* OVZP x%a
**SiteInfoBean.java D93gH1z
*/ U9 #w
package NetFox; 3f"C!l]Xu
V43TO
AotCX7T2T
public class SiteInfoBean { dN< ,%}R
|#k@U6`SG
/2xSNalC
private String sSiteURL; //Site's URL 5MR,UgT
private String sFilePath; //Saved File's Path M diwRi
private String sFileName; //Saved File's Name Lkn4<'un
private int nSplitter; //Count of Splited Downloading File )qv2)a!H
cLG6(<L
`<U5z$^QTw
public SiteInfoBean() &dr@6-xaq
{//nSplitter的缺省值为5 Or8kp/d
//default value of nSplitter is 5 {WQq}-(
this("","","",5); z8"7u/4v{
} X%4Kj[I^
BJk Z2=
:QPf~\w?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !X]8dyW
{ ; b*i3*!g
sSiteURL= sURL; wP<07t[-g
sFilePath = sPath; 9%tobo@J~n
sFileName = sName; ?IF)+]
this.nSplitter = nSpiltter; q9]IIv
+.kfU)6@
aJzLrX
} 5Sva}9H
i{Ds&{
]Y`Ib0$
public String getSSiteURL() ]{GDS! )
{ `XKVr
return sSiteURL; 2YlH}fnH
} <%P2qgz5
YlF%UPp
}Wh6zT)
public void setSSiteURL(String value) O9"/ kmB
{ ypdT&5Mqb!
sSiteURL = value; F(,UA+$A
} F_H82BE+3
-7{$Vj
!.TLW
public String getSFilePath() k{I01
{ IzLQhDJ1
return sFilePath; S DLvi!y
} p B;3bc
OLC{iD#
#oni:]E!m
public void setSFilePath(String value) 8}s.Fg@tE
{ Wwujh2g"0|
sFilePath = value; 5jxQW ;
} ,yd=e}lQx
jMNU ?m:
\S~Vx!9w
public String getSFileName() hrGH}CU"
{ 2*iIjw3g
return sFileName; 9f+>ix,ek*
} OTDg5:>
umi5Wb<
QPtGdd
public void setSFileName(String value) Q[F}r`
{ Z|"p*5O,
sFileName = value; ?>"Yr,b?
} T"7~AbgNU
*3/T;x.
a^d8I
public int getNSplitter() ?L&|Uw+
{ YH&bD16c3
return nSplitter; ^z6_Uw[
} YuZ"s55zU{
V'*~L\;pU
]e.JNo
public void setNSplitter(int nCount) +)o}c"P!
{ [ i#zP
nSplitter = nCount; $/!{OU.t`
} ;JZS^Wa
} dT,o=8fg
hW!)w
P) 3mX.(}
/* y6]vl=^L
**Utility.java E4m`
*/ Y"A/^]
package NetFox; a5a($D
y~()|L[
Sb~MQ_
public class Utility { RV@*c4KvO+
C z\Ppq
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public Utility() sc,Xw:YO
{ 0}_[DAd6
M Y|w
x c{hC4^V
} ~NW32 O)/
GnvL'ESa@M
//线程睡眠 h@a+NE8
public static void sleep(int nSecond) rRFhGQq1m
{ XQw>EZdj_N
try{ Ja9e^`i;
Thread.sleep(nSecond); VkZ7#
} Yk=PS[f
catch(Exception e) ~6p[El#tS
{ ,cNLkoN
e.printStackTrace (); YpqrZWvh
} >y,-v:Vy
} r?/'!!4
K.0:C`C
//日志 ~c\e'&sc;
public static void log(String sMsg) x)@G;nZ
{ b9!FC$^J
System.err.println(sMsg); R rda# h^
} *c2YRbU(
EVGt 5z
>rf'-X4n
public static void log(int sMsg) Y=Kc'x[,Zj
{ ~;N^g4s
System.err.println(sMsg); x@[rms
} 9E6_]8rl
} _ jsK}- \
"yS _s
s=;uc]9g
/* .nVa[B|.
**TestMethod.java }|pwz
*/ 9?SZNL['V
package NetFox; :>C2gS@
sr{a(4*\
H5Io{B%=
public class TestMethod { ,=[?yJy
ye,>A.
oaIi2=Tf
public TestMethod() W>j!Q^?
{ ///xx/weblogic60b2_win.exe MB~=f[cUnd
try{ ^y<<>Y'I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XMxSQ B1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uc){+'[
SiteFileFetch fileFetch = new SiteFileFetch(bean); c"B{/;A
fileFetch.start(); T[g[&K1Y
} .N ,3od@
catch(Exception e){e.printStackTrace ();} 1ng!G 7g
kH G"XTL
zem8G2#c
} ~f$|HP}
|#]@Z)xa
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public static void main(String[] args) 7/I,HxXp!
{ UG+d-&~Ll
new TestMethod(); Uq^#riq
} jIC_[
} old(i:2
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