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)); ,uK }$l
} bm`x
for(int i=0;i<nEndPos.length-1;i++) X8y&|uH
{ }zj_Pp
nEndPos = nStartPos[i+1]; ?3"lI,!0
} qK,rT*5=
nEndPos[nEndPos.length-1] = nFileLength; Me2%X>;
} ?>DN7je
} {0QNqjue
mM!Gomp
4Bs '5@
//启动子线程 CKy' 8I9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8)/d8@
for(int i=0;i<nStartPos.length;i++) J?LetyDNr]
{ O_*%_S}F&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3Vs8"BFjz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }~y i6!w'
nStartPos,nEndPos,i); M;-PrJdyt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7S}NV7
fileSplitterFetch.start(); g-Vxl|hR
} d3<7t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sA#}0>`3S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^#KkO3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _?CyKk\I
nEndPos = " + nFileLength); >-0Rq[)
// fileSplitterFetch[nPos.length-1].start(); 0EKi?vP@y7
k`_sKr]9
;M1#M:
//等待子线程结束 +9<"Y6
//int count = 0; }&F|u0@b
//是否结束while循环 mA@FJK_
boolean breakWhile = false; W2&o'(P\
6g576
n#|ljC
while(!bStop) _<qe= hie!
{ #~BsI/m
write_nPos(); =+DfIO
Utility.sleep(500); #p*D.We
breakWhile = true; +DU^"q=
=;ClOy9
i}[cq_wJ
for(int i=0;i<nStartPos.length;i++) j4k\5~yzS
{ gF#HNv
if(!fileSplitterFetch.bDownOver) e#!%:M;4P
{ 3K!(/,`
breakWhile = false; jmPnUn
break; |Bz1u|uc
} c#(Hh{0
} -Aaim`06bv
if(breakWhile) vhIZkz!9
break; m Q4(<,F
G5vp(%j
FUzN}"\1
//count++; JlR$"GU
//if(count>4) ~@=(#tO.
// siteStop(); }IEwGoDwNs
} =h0vdi%{
%;_94!(hC
Xdh2
System.err.println("文件下载结束！"); ^F,sV*
} 2. '` mGu
catch(Exception e){e.printStackTrace ();} B>.x@(}V~
} &OYo
ORuC("
K*I!:1;3N
//获得文件长度 UE8j8U'L
public long getFileSize() @GUlw[vi
{ j 5}'*
int nFileLength = -1; 4Hy/K^Ci
try{ 5(>SFxz"t
URL url = new URL(siteInfoBean.getSSiteURL()); O,6Wdw3+-3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MH=7(15R
httpConnection.setRequestProperty("User-Agent","NetFox"); VWq]w5oQO
'_d4[Olu
o1`\*]A7J
int responseCode=httpConnection.getResponseCode(); I+=+ ,iXhB
if(responseCode>=400) p<1y$=zS
{ A:yHClmn
processErrorCode(responseCode); 3P@D!lV&K
return -2; //-2 represent access is error 5skxixG
} [?%q,>F
>)F "lR:o
zD)/QFILy
String sHeader; ]Hp>~Zvbb
XeX\u3<D
n{u\t+f
for(int i=1;;i++) &AN1xcx\
{ B (Ps/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cbN;Kv?ak}
//Utility.log(in.readLine()); Mg#yl\v
sHeader=httpConnection.getHeaderFieldKey(i); >-w(P/
if(sHeader!=null) $=iw<B r
{ _%q~K (::
if(sHeader.equals("Content-Length")) jp_|pC'
{ =Ox}WrU~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #x;,RPw5
break; />Q}0Hg
} aaP_^m O
} wBcoh~ (y
else q3AqU?f
break; 0j_kK
} c/Xg ARCO
} h2 KI
catch(IOException e){e.printStackTrace ();} 7:,f|>
catch(Exception e){e.printStackTrace ();} 9w$m\nV
=:aJZ[UU<2
*,mI=1
Utility.log(nFileLength); AHRJ7l;a
gVrQAcJj
J$Z=`=]t+
return nFileLength; 2]1u0-M5L
} }x?F53I)
h%:rJ_#Zl
4;fuS_(X
//保存下载信息（文件指针位置） LRVcf
private void write_nPos() l%T4:p4e
{ U@M3.[jw
try{ Hs*["zFc
output = new DataOutputStream(new FileOutputStream(tmpFile)); T]\c2U
output.writeInt(nStartPos.length); TP"cEfs x
for(int i=0;i<nStartPos.length;i++) I]^>>>p$
{ L8 L1_
// output.writeLong(nPos); wqhktgG
output.writeLong(fileSplitterFetch.nStartPos); ,Klv[_x7
output.writeLong(fileSplitterFetch.nEndPos); =}vT>b
} "|h%Uy?XY
output.close(); - 8p!,+Dk
} nq)F$@
catch(IOException e){e.printStackTrace ();} z@yTkH_
catch(Exception e){e.printStackTrace ();} [ n7>g
} $P=C7;
*!%lBt{2
U}LW8886
//读取保存的下载信息（文件指针位置） =eDIvNps
private void read_nPos() * :O"R
{ `&M,B=E
try{ sU"%,Q5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H_X^)\oJ
int nCount = input.readInt(); 9<6q(]U
nStartPos = new long[nCount]; ovdJ[bO
nEndPos = new long[nCount]; hbJ>GSoZ,
for(int i=0;i<nStartPos.length;i++) z5kAf~A
{ $iu[-my_
nStartPos = input.readLong(); .!x&d4;,q
nEndPos = input.readLong(); fbNzRXw
} X` zWw_i
input.close(); gv''A"
} unLhI0XW
catch(IOException e){e.printStackTrace ();} TIWR[r1!
catch(Exception e){e.printStackTrace ();} (k?HT'3)
} G3~`]qf
d~Z\%4
b6bs .
private void processErrorCode(int nErrorCode) yOq@w!xz
{ wT4@X[5$
System.err.println("Error Code : " + nErrorCode); E5w;75,
} 9af.t
qI+2,6 sGI
J;C:nE|V
//停止文件下载 1u 9hA~rj
public void siteStop() '+`[)w
{ iRzFA!wH
bStop = true; <s9?9^!!V^
for(int i=0;i<nStartPos.length;i++) cJ;Nh>ey
fileSplitterFetch.splitterStop(); ~SnUnNDm`
j*jUcD*
Z!)~?<gcq:
} ilA45@
} 0NXH449I=
//负责部分文件的抓取 5% 2A[B
**FileSplitterFetch.java }yz>(Pq
*/ # ]7Lieh[5
package NetFox; *\sPHz.
;2p+i/sVj
D|N4X`T`
import java.io.*; .Q{RTp
import java.net.*; Bqq=2lj
an"&'D}U
Zh=arlk
public class FileSplitterFetch extends Thread { 2 T!Tiu
9}(w*>_L
558P"w0"X
String sURL; //File URL 9a}9cMJ^"
long nStartPos; //File Snippet Start Position <$A,Ex94
long nEndPos; //File Snippet End Position c0qp-=^&.
int nThreadID; //Thread's ID fpD$%.y'J
boolean bDownOver = false; //Downing is over 54gr'qvr
boolean bStop = false; //Stop identical -U d^\Yy
FileAccessI fileAccessI = null; //File Access interface K3T.l#d'L
6l#x1o;
,NSf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Mo,&h?VOM?
{ U1[)eD`
this.sURL = sURL; /wV|;D^ )
this.nStartPos = nStart; 3Q=^&o0fl
this.nEndPos = nEnd; l":W@R
nThreadID = id; Ri.tA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mj~:MCC
} LeKovt%
H@Dpht>[
"Ms;sdjg}&
public void run() 0j.K?]f)h
{ E}@C4pS
while(nStartPos < nEndPos && !bStop) RkF#NCnL;
{ >STtX6h
eS`VI+=@0
]A*}Dem*5
try{ OtG\Uw8
URL url = new URL(sURL); rE3dHJN;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P@{x@9kI
httpConnection.setRequestProperty("User-Agent","NetFox"); UUah5$Iy
String sProperty = "bytes="+nStartPos+"-"; i0vm00oT
httpConnection.setRequestProperty("RANGE",sProperty); ag-A}k>v
Utility.log(sProperty); X8nos
dzf2`@8#
eqbN_$>
InputStream input = httpConnection.getInputStream(); Cp8=8N(Xb
//logResponseHead(httpConnection); Nwvlv{k'
RB5SK#z
v pI9TG
byte[] b = new byte[1024]; XYEwn_Y
int nRead; IG781:,/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fab'\|Y
{ ,X4e?$7g
nStartPos += fileAccessI.write(b,0,nRead); jvzioFCt
//if(nThreadID == 1) #36QO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g^AQBF
} 34@[ZKJ5
8v4}h9*F"7
);5o13h2
Utility.log("Thread " + nThreadID + " is over!"); >4:d)
bDownOver = true; ~>2uRjvkwB
//nPos = fileAccessI.write (b,0,nRead); k3~9;Z
} ]v+<K63@T
catch(Exception e){e.printStackTrace ();} U7r8FLl
} nbi7rcT
} {o=?@$6C
NGx3f3 9
| f#wbw
//打印回应的头信息 8nz({Mb9Z
public void logResponseHead(HttpURLConnection con) U{U"%XdO
{ Q;M\fBQO}&
for(int i=1;;i++) ?,} u6tH
{ $3-vW{<
String header=con.getHeaderFieldKey(i); +>$]leqa
if(header!=null) }F`|_8L*v)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oMh$:jR$
Utility.log(header+" : "+con.getHeaderField(header)); 0RUk^
else 6Rc=!_v^
break; Knq9"k
} 'h>uR|
} 9t`;~)o
$TQhr#C]
&!!*xv-z
public void splitterStop() LQ+/|_(.
{ ?jx]%n fV
bStop = true; VF]AH}H8I
} nm'l}/Ug
dC11kqqj
_z\/{
} /d`"WK,
^^y eC|~N:
fgLjF,Y
/* G7Nw}cVJ)
**FileAccess.java / 3A6xPOg
*//文件访问(定位，写) *Gsj pNr-
package NetFox; +y7z>Fwl
import java.io.*; ua\t5M5
kaG/8G(
X>q`F;W
public class FileAccessI implements Serializable{ gI+8J.AG=
FG?Mc'r&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fi+}hGj(r
RandomAccessFile oSavedFile; .[|UNg
long nPos; SZykG[
iD^,O)b
Jt~Ivn,
public FileAccessI() throws IOException hI[} -
{ 3jmo[<p*x
this("",0); .@1+}0
} -m@o\9Ic
h`[$ Bp
,75)
public FileAccessI(String sName,long nPos) throws IOException *~rj!N?;
{ Q eeV<
oSavedFile = new RandomAccessFile(sName,"rw"); "wUIsuG/p
this.nPos = nPos; 7"(!]+BW!O
oSavedFile.seek(nPos); .)Tj}Im2p
} rhv~H"qzW
3Ax'v|&Hg
]#!uke Q
public synchronized int write(byte[] b,int nStart,int nLen) ((y|?Z$
{ kA:Y^2X'
int n = -1; Fs+tcr/\[
try{ O zAIz+`
oSavedFile.write(b,nStart,nLen); 4kOO3[r
n = nLen; #-{<d%qk
} U,P_bz*)
catch(IOException e) k.J%rRneN
{ [4)Oi-_Y>
e.printStackTrace (); UwN Vvo
} `L1,JE` q
P_bB{~$4
z8kO)'
return n; 3%WB?kc
} Gnc`CyN:H
Q|y}mC/
Psb !Z(
} Pt]>AW;i
Zxk~X}K\P
ffKgVQux
/* s%[F,hQRk
**SiteInfoBean.java |/.J{=E0K
*/ ]a3$hAcj6"
package NetFox; AFLtgoXn:
?K1B^M=8
cNll??j
public class SiteInfoBean { tV}!_
h~dQ5%
)p&g!qA
private String sSiteURL; //Site's URL ^FCXcn9
private String sFilePath; //Saved File's Path :X2_#qW#C
private String sFileName; //Saved File's Name }{0}$#zu
private int nSplitter; //Count of Splited Downloading File mz?<t/$U
So%X(, |
fN vQ.;
public SiteInfoBean() RTtKf i}
{//nSplitter的缺省值为5 C{)1#<`
//default value of nSplitter is 5 C6+ 5G-Z
this("","","",5); O\}C`CiC
} YAi-eL67l
Cq5.gkS<
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kHM Jh~
{ ]m1fo'
sSiteURL= sURL; 5Cf!NNV
sFilePath = sPath; Y,]Lk<Hm3
sFileName = sName; 3:nhZN/95T
this.nSplitter = nSpiltter; s 6Wp"V(
BR|!ya+_2
u=`H n-(
} .1QGNW
,0'GHQWz$
j cd<'\;
public String getSSiteURL() pwSgFc$z
{ iUkUo x
return sSiteURL; 5(;Y&?k
} Ou[K7-m%&
p.8bX
79DNNj~
public void setSSiteURL(String value) ixTjXl2g
{ jCd]ENl+_
sSiteURL = value; ]3r}>/2(
} .ARYCTyG
F`=p/IAJK
0d2P
public String getSFilePath() (3e.q'
{ 4:MvC^X~z
return sFilePath; Jb,54uN
} .G/Rh92
vG|!d+
z']6C9m}
public void setSFilePath(String value) xj5TnE9^
{ KGt:
sFilePath = value; KpN]9d
} XG#?fr}L
&YFe"C
>N&{DJmD
public String getSFileName() #.8v[TkKq
{ lKbWQ>
return sFileName; )x-b+SC
} s,R:D).
T CT8OU|
74^v('-2
public void setSFileName(String value) Iv6 lE:)
{ FDoPW~+[
sFileName = value; txEN7!
} Z% +$<J
4*_jGw
lHiWzt u
public int getNSplitter() ~[H8R|j "
{ .Ys e/oEo
return nSplitter; 2EgvS!"
} @@R Mm$
]*dYX=6
s|IBX0^@
public void setNSplitter(int nCount) OvH:3"Sdy
{ EBhdP
nSplitter = nCount; # epP~J_f
} wv~:^v'
} @Y0ZW't
xMbgBx4+
.!1[I{KU
/* 3f=ZNJ>
**Utility.java sY<UJlDKT
*/ ~[=<Os
package NetFox; S1|5+PPs
$f@YQN=
?N4FB*x
public class Utility { .!q_jl%U
coCT]<
Na@bXcz)
public Utility() Z?P^Y%ls
{ jCY~Wc
c5p,~z_Dtu
(wj:Gc
} ?}`-?JB1
c0wLc,)G
//线程睡眠 !'_7MM
public static void sleep(int nSecond) !B`z|#
{ F{mUxo#T
try{ ;R=n<=Axa
Thread.sleep(nSecond); R_!'=0}V
} l/k-`LeW
catch(Exception e) )qx;/=D
{ G]h_z|$K
e.printStackTrace (); B=KrJ{&!
} $SQ$2\iC
} [IHo ~
2G.y.#W
//日志 _DxHJl
public static void log(String sMsg) cs6oD!h
{ 5mamWPw
System.err.println(sMsg); L#SW!
} ?|,:;^2l1
GZO:lDdA
fXWy9 #M
public static void log(int sMsg) %NQ mV_1
{ k'r}@-X
System.err.println(sMsg); yeyDB>#Va.
} h: yJ
} f?d5Ltg
=]%,&Se
/KvJjt'8
/* _Q:z -si
**TestMethod.java OUWK
*/ brp3xgQ`]
package NetFox; DpggZ|J
)bM,>x
z5gVP8*z5
public class TestMethod { UvGxA[~2+
7:B/?E
3;buC|ky
public TestMethod() 4Q!A w
{ ///xx/weblogic60b2_win.exe m 3UK`~ji
try{ M|c_P)7ym
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uZ8-?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Xz@#,F:@
SiteFileFetch fileFetch = new SiteFileFetch(bean); u7mPp3ZYK
fileFetch.start(); "BsK'yo.
} ^g4Gw6q6
catch(Exception e){e.printStackTrace ();} PVg<Ovi^d
' pgPQM<
ZBDF>u@
} t+w{uwEY
aX1b(h2
u<8b5An;
public static void main(String[] args) dnomnY(*<
{ *%/O (ohs@
new TestMethod(); zG$5g^J
} t Cb34Wpf
} n UmyPQ~
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