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)); rw%1>]os
} Mx_O'D
for(int i=0;i<nEndPos.length-1;i++) 54>gr1B
{ {-.ZFUZmT
nEndPos = nStartPos[i+1]; &!0%"4
} ZK$<"z6{
nEndPos[nEndPos.length-1] = nFileLength; bPHtP\)
} Rpou.RrXR7
} 8%#pv}
]>H'CM4JR
w[hT,$n
//启动子线程 OTV$8{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I*OJPFZ^4
for(int i=0;i<nStartPos.length;i++) QNxY`
{ Mcm%G#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L)-1( e<x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TV[@!E a
nStartPos,nEndPos,i); H?$gHZPI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (GB*+@
fileSplitterFetch.start(); :7 OhplI
} Rt3/dw(p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "C'T>^qw*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u3])_oj=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~=i<O&nai
nEndPos = " + nFileLength); jPA^SxM
// fileSplitterFetch[nPos.length-1].start(); &KPJB"0L
WwAvR5jq
3R)_'!R[B
//等待子线程结束 \>lDM
//int count = 0; |]+PDc%
//是否结束while循环 ^J?y mo$>0
boolean breakWhile = false; [a!*m<
Z?j4WJy-[
2YhtD A
while(!bStop) :WHbwu,L$
{ KreF\M%Ke
write_nPos(); 5sI9GC
Utility.sleep(500); #{x4s?
breakWhile = true; pL pBP+i
I`4k5KB;
m'YYkq(5%Z
for(int i=0;i<nStartPos.length;i++) B0dv_'L}L
{ ]m@p? A$
if(!fileSplitterFetch.bDownOver) iJVm=0WS^
{ +_v#V9?
breakWhile = false; mz?1J4rt
break; Fa-F`U@h(m
} 2{I+H'w8:
} }KFM8CbS
if(breakWhile) g ^4<ve
break; {1m.d;(1
XO,gEn&6V
tA{?-5
//count++; xXfFi5Eom
//if(count>4) _(0GAz%9
// siteStop(); vuO~^N]G
} =5u;\b>*
(8jQdbZU
st-I7K\v
System.err.println("文件下载结束！"); f\h|Z*Bv
} = @n`5g
catch(Exception e){e.printStackTrace ();} 1,Ji|&Pwf
} q:-1ul
cC7&]2X +f
w i=&W
//获得文件长度 1qd(3A41
public long getFileSize() d6+{^v$#
{ 5~\GAjf
int nFileLength = -1; %W,V~kb
try{ A`ScAzx5{
URL url = new URL(siteInfoBean.getSSiteURL()); uG{/yJeU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HrH! 'bd
httpConnection.setRequestProperty("User-Agent","NetFox"); #xfPobQ>il
0p[-M`D
4)+L(KyB2
int responseCode=httpConnection.getResponseCode(); .y^T3?}I
if(responseCode>=400) 9KDm<Q-mf
{ Rn5{s3?F~2
processErrorCode(responseCode); YW'l),Z
return -2; //-2 represent access is error {LoNp0i1a
} #S') i1;
U2kl-E:
thrv_^A
String sHeader; 2R>!Wj'G+o
DhzmC
KxUO=v<u
for(int i=1;;i++) {D7v[P+
{ K\y W{y1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); DE!P[$J
//Utility.log(in.readLine()); 4M*!'sG\
sHeader=httpConnection.getHeaderFieldKey(i); ql(~3/kA_
if(sHeader!=null) )bR`uV9<
{ [6cf$FS9
if(sHeader.equals("Content-Length")) u]jvXPE6
{ z-G*:DfgH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1CA%nqlng
break; }x(Ewr
} gN5;Uk
} /\d@AB^5I
else =L&dV]'4P
break; 9 gWqs'
} 5[|ZceY
} qz&?zzz;
catch(IOException e){e.printStackTrace ();} u?lbC9}$
catch(Exception e){e.printStackTrace ();} 5 ]l8l+
TpAso[r
(;cvLop
Utility.log(nFileLength); U]64HuL
%WAaoR&u
H rI(uZ]
return nFileLength; lCiRvh1K
} e(Y5OTus
'-M9v3itC
&"mWi-Mpl
//保存下载信息（文件指针位置） ~R C\
private void write_nPos() zp:EssO=Q
{ <(W:Q3?s
try{ xY<*:&
output = new DataOutputStream(new FileOutputStream(tmpFile)); y?ypRCgO.u
output.writeInt(nStartPos.length); HA]5:ck
for(int i=0;i<nStartPos.length;i++) T/iZ"\(~w
{ )kvrQ6
// output.writeLong(nPos); |ohCA&k%;
output.writeLong(fileSplitterFetch.nStartPos); v9XevLs
output.writeLong(fileSplitterFetch.nEndPos); =} flmUv~
} E?cf#;2h8m
output.close(); ]3I@5}5%
} m)e~HP7M
catch(IOException e){e.printStackTrace ();} rB}2F*eT
catch(Exception e){e.printStackTrace ();} ^C70b)68
} [,Fu2j]
Ob@HzXH
n7(/ml+Q_
//读取保存的下载信息（文件指针位置） ?#Y1E~N
private void read_nPos() u -A_l<K
{ wrAcVR
try{ bD<hzOa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H-jxH,mJmW
int nCount = input.readInt(); (Ky$(Ubb#6
nStartPos = new long[nCount]; JGQ)/(
nEndPos = new long[nCount]; ,)Z1&J?
for(int i=0;i<nStartPos.length;i++) *Z2#U?_
{ #@}wl
nStartPos = input.readLong(); \vF*n Z5/
nEndPos = input.readLong(); aqKrf(Rv
} )W |_f
input.close(); _FP'SVa}D
} Eu`K2_b
catch(IOException e){e.printStackTrace ();} p61F@=EL
catch(Exception e){e.printStackTrace ();} @f`s%o
} iG+=whvL
ChRCsu~
O~D]C
private void processErrorCode(int nErrorCode) grTwo
{ !]l;n Fd
System.err.println("Error Code : " + nErrorCode); g4}K6)@
} Nc:0opPM
:aWC6"ik-W
$\q}A:
//停止文件下载 l,:>B-FV
public void siteStop() 5~{s-Ms
{ _NN5e|t
bStop = true; ]^I[SG,
for(int i=0;i<nStartPos.length;i++) H'%#71
fileSplitterFetch.splitterStop(); Nbd[xs-lw
sDP8!
} bm ^`QY
} ]+d>;$O
} 'pC51}[A{^
//负责部分文件的抓取 C(&3L[
**FileSplitterFetch.java tb;u%{S
*/ 51Q~/
package NetFox; vBYk"a6SD
#BwOWra
j W/*-:
import java.io.*; ->`R[k
import java.net.*; ];*?`}#
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A9o"L.o)
public class FileSplitterFetch extends Thread { ub]"b[j\1
5v"Sv
2 sK\.yS
String sURL; //File URL <8BNqbX
long nStartPos; //File Snippet Start Position %:yVjb,Yf
long nEndPos; //File Snippet End Position Vu;z|L
int nThreadID; //Thread's ID J7p?9
boolean bDownOver = false; //Downing is over Vw+RRi(
boolean bStop = false; //Stop identical +k\cmDcb
FileAccessI fileAccessI = null; //File Access interface }TRVCF1
+l;AL5h
b] ~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?<U">8cP
{ S^_F0</U,
this.sURL = sURL; @waY+sqt=
this.nStartPos = nStart; S=qx,<J 39
this.nEndPos = nEnd; 2>/}-a
nThreadID = id; q@XxCP]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 iyP0;$
} kerBy\^
TnJJ& "~3b
Ny G?^
public void run() #]z_pp:
{ @6%o0p9zz
while(nStartPos < nEndPos && !bStop) M?QX'fia
{ O6n]l
l(d3N4iz
#A=ER[[
try{ hE;BT>_dn
URL url = new URL(sURL); zR5KC!xc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3 uJ?;
httpConnection.setRequestProperty("User-Agent","NetFox"); qz8Jvgu?
String sProperty = "bytes="+nStartPos+"-"; W~Q;R:y
httpConnection.setRequestProperty("RANGE",sProperty); oa6&?4K?F
Utility.log(sProperty); RLbo
1"~$(@oxG
0,j!*
InputStream input = httpConnection.getInputStream(); }NKnV3G/Z
//logResponseHead(httpConnection); l!j,9wz7
DeTLh($\
G<Y}QhFU
byte[] b = new byte[1024]; -YY@[5x?u
int nRead; {9-n3j}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0X}0,
{ sF~!qag4q'
nStartPos += fileAccessI.write(b,0,nRead); qv3% v3\4
//if(nThreadID == 1) #7=- zda5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n a+P|'6
} }s:~E2?In
eDY)i9"W
PLRMW2
Utility.log("Thread " + nThreadID + " is over!"); }-~LXL%!3
bDownOver = true; Rk!8eN Pf
//nPos = fileAccessI.write (b,0,nRead); vfdTGM`3
} rY295Q
catch(Exception e){e.printStackTrace ();} \nU_UH
} a LJ d1Q
} Ww=b{lUD
<jG[ z69)
["sm7yQ
//打印回应的头信息 CvRO'
public void logResponseHead(HttpURLConnection con) q``:[Sz
{ *+_+ZDU
for(int i=1;;i++) C sCH :>
{ mb*|$ysPx
String header=con.getHeaderFieldKey(i); uMX\Y;N
if(header!=null) F~?|d0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z31a4O
Utility.log(header+" : "+con.getHeaderField(header)); w#{S=^`}
else iC~ll!FA!
break; }ZJJqJ`*e
} .p(%gmOp#
} ~8U0(n:^
pyp0SGCM:
>tE6^7B*
public void splitterStop() #,9#x]U#v
{ qm< mw"]
bStop = true; _ O;R
} \`R8s_S
Fb6d1I^wR
#~[{*[B+
} ^Vg-fO]V
xB5QM #w\
u,./,:O%=
/* s&1}^'|
**FileAccess.java v\D.j4%ij
*//文件访问(定位，写) N5.kDT
package NetFox; BH0s` K"
import java.io.*; :ZadPn56
C4)m4r%
mI5!rrRD|
public class FileAccessI implements Serializable{ >1$Vh=\OI
'cA(-ghY/E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PQP|V>g
RandomAccessFile oSavedFile; KpT=twcK
long nPos; rp=Y }
w%-S5#
,,]<f*N
public FileAccessI() throws IOException wK0],,RN,h
{ r!~6.
this("",0); |q c<C&O
} d&naJ)IoF)
.0p'G}1
Ll, U>yo
public FileAccessI(String sName,long nPos) throws IOException X'j9l4Ph7
{ yz=aJ v; H
oSavedFile = new RandomAccessFile(sName,"rw"); /Ow@CB
this.nPos = nPos; myF/_o&Ty
oSavedFile.seek(nPos); p# |} o9
} onl,R{,`0
(U@$gkUx}G
5,?^SK|'x
public synchronized int write(byte[] b,int nStart,int nLen) B`:l;<&jX
{ f o idneus
int n = -1; TQth"Cv2:
try{ 1p8hn!V
oSavedFile.write(b,nStart,nLen); T\"-q4+=C
n = nLen; (wf3HEb_
} OoQLR
catch(IOException e) mDO! o
{ ZE9.r`
e.printStackTrace (); "O~kIT?/v
} 49YN@PXC
mJYD"WgY
A_crK`3
return n; /!fJ`pu!
} gBOF#"-
Hyi'z1
F?t;bV
} 3Hi8=*
7"1]5\p^g
$g),|[x+(
/* `pF7B6[B
**SiteInfoBean.java &Bqu2^^
*/ i&{%}==7
package NetFox; ;9LOeH?
=MT'e,T
XSGBC:U)l
public class SiteInfoBean { =|dHD
V>D}z8w7
,&L}^Up
private String sSiteURL; //Site's URL V[n,fEPBr
private String sFilePath; //Saved File's Path ja6V*CWb
private String sFileName; //Saved File's Name %M:$ML6b<
private int nSplitter; //Count of Splited Downloading File fk!9` p'
sG\K$GP!
]E6r)C
public SiteInfoBean() x"r,l/gzy
{//nSplitter的缺省值为5 k8r1)B4ab
//default value of nSplitter is 5 wNU;gz
this("","","",5); j4u ["O3
} M3r;Pdj2r
VOIni<9y
e^;%w#tEqI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P3nBxw"
{ dsH*9t:z
sSiteURL= sURL; TFAR>8Nm
sFilePath = sPath; VfozqUf
sFileName = sName; Wb[k2V
this.nSplitter = nSpiltter; ("{"8
}Rw6+;
X4{<{D`0t8
} "Q{l])N
| AiMx2
EWr7eH
public String getSSiteURL() 0T^0)c
{ )?pnV":2Y
return sSiteURL; )j\_*SoH
} q@tym5
)sNPWn8<Uy
=3!o_
public void setSSiteURL(String value) p$uPj*
{ *f_A:`:
sSiteURL = value; 7iyx_gyo
} M8/:PmR<
XUnw*3tPJ
T#wG]DH;
public String getSFilePath() pRd'\+
{ vPc*x5w-
return sFilePath; ,HI%ym
} Io[NN aF|
Qqx!'fft
Cy*.pzCi
public void setSFilePath(String value) :wG )
{ kdp^{zW}
sFilePath = value; #Ge_3^'
} jOzi89
^bP`Iv
zWH)\>X59
public String getSFileName() x,zYNNx5g
{ ib~i ^_p
return sFileName; lQBEq"7$
} 7?{y&sf
`'&mO9,<-
J_;*@mW
public void setSFileName(String value) QZIzddwp
{ ('AAHq/
sFileName = value; HUAYtUBH
} paLPC&G
W6_rSVm
o8|qT)O@U
public int getNSplitter() v$w}UC%uf
{ p|8ZHR+
return nSplitter; {f@Q&(g
} vbd)L$$20+
/'5d0' ,M
\P")Eh =d
public void setNSplitter(int nCount) V)l:fUm2
{ Dh}(B$~Oz+
nSplitter = nCount; 'nBP%
} vZ811U~}
} GC'e
ir"t@"Y;o
=5Nh}o(l?
/* O ;[Mi
**Utility.java z;F HZb9t,
*/ O"Nr$bS(Y
package NetFox; RRV%g!
K&Bbjb_|
Em^~OM3U$q
public class Utility { I "O^.VC
j7lJ7BIr
CtV|oeJ
public Utility() &$ "J\vm
{ ^X}r ^
^L)TfI_n
MfHOn YV
} 6@t&
.xWaS8f
//线程睡眠 K3M.ZRh\;`
public static void sleep(int nSecond) '^>} =f
{ k sXQ}BE
try{ #QIY+muN
Thread.sleep(nSecond); 4(LLRzzW
} h`dQOH#
catch(Exception e) BgQ/$,
{ J?yasjjgP
e.printStackTrace (); BxjSo^n
} RL/y7M1j
} [P =P8-5
A[ncwJ
//日志 MP)Prl>
public static void log(String sMsg) kfZ`|w@q
{ u~ipB*Zf
System.err.println(sMsg); aHmg!s}&
} $ P5K
Pd\4hy
NsP=l]
public static void log(int sMsg) <kPNe>-f
{ ZTV)D
System.err.println(sMsg); ]%HxzJ
} FHw%ynC
} Mms|jFoQ
yn_f%^!G
-0#"<!N
/* z!O;s ep?/
**TestMethod.java #dL,d6a
*/ rKUtTj
package NetFox; 0NGth(2
z k/`Uz
6QCVi
public class TestMethod { W"\}##
J8p;1-C"
n]`]gLF\i
public TestMethod() ndzADVP
{ ///xx/weblogic60b2_win.exe a1y<Y`SC9
try{ Um{) ?1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {?0'(D7.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %UrNPk
SiteFileFetch fileFetch = new SiteFileFetch(bean); -^2p@^
fileFetch.start(); b4-gNF]Yt
} SsTBjIX
catch(Exception e){e.printStackTrace ();} 6qFzo1LO
uX3yq<lK"
?'+]d;UO&
} cZ|*Zpk
D]fuX|f~ul
v:QUwW
public static void main(String[] args) )'T].kWW
{ i0K 2#}=^
new TestMethod(); PdqvXc
} ?Y3i-jY
} Zf3(! a[
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