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)); {$Fg+~
} %'EOFv]
for(int i=0;i<nEndPos.length-1;i++) w,JB`jS)/
{ &.Yh_
nEndPos = nStartPos[i+1]; U7 Z_
} +mV4Ty
nEndPos[nEndPos.length-1] = nFileLength; qb "H&)aHw
} R+, tn,<<
} v#D9yttO{
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f'R^MX2
//启动子线程 ]y!|x_5c3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _X;5ORH"
for(int i=0;i<nStartPos.length;i++) W^al`lg+y
{ $Ne#F+M9x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e 0!a &w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k(hes3JV
nStartPos,nEndPos,i); N6yqA)z?;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {f)",#
fileSplitterFetch.start(); {P-KU RQ
} }^P(p?~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -Z]?v3 9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m.S@ e8kS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &*L:4By)]
nEndPos = " + nFileLength); TvMY\e
// fileSplitterFetch[nPos.length-1].start(); }GQ8|fg`U
<[[DS%(M^
&~^"yo#b
//等待子线程结束 bg[q8IBCd
//int count = 0; vNi7=3
//是否结束while循环 b^^Cj(
boolean breakWhile = false; ~])\xC
K3'`!Ka*
PX(Gx%s|
while(!bStop) z26zl[.
{ B2&fvv?
write_nPos(); ^|as]x!sv
Utility.sleep(500); ].2q.7Yur
breakWhile = true; WihOGdUS6
=^=9z'u"=
y&9v0&o
for(int i=0;i<nStartPos.length;i++) +<@7x16
{ "D8xHHb
if(!fileSplitterFetch.bDownOver) uXu'I
{ q^Oq:l$s
breakWhile = false; (!{_O_&
break; /gXli)
} luLm:NWUM
} \wO)w@"
if(breakWhile) pk(<],0]X
break; g:e|
>RE&>T^8
<k}>eGn
//count++; _W tSZmW?
//if(count>4) t`H^! b
// siteStop(); b 3D:w{l
} GEIMCg(TRj
$U"/.Mh\
mMu3B2nke=
System.err.println("文件下载结束！"); E{Y0TZ+
} KdYT5VUM/
catch(Exception e){e.printStackTrace ();} u.8vXc
} )d0&iE`@
k/!Vv#8
w0tlF:Eg
//获得文件长度 tkV:kh< L~
public long getFileSize() HC}D<FX|
{ D@5&xd_@4
int nFileLength = -1; Lg_y1Mu7o
try{ 9?bfZF4A=
URL url = new URL(siteInfoBean.getSSiteURL()); +z;xl-*[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +6uun
httpConnection.setRequestProperty("User-Agent","NetFox"); r/:s2oQ
mmr>"`5.
,LWM}L
int responseCode=httpConnection.getResponseCode(); S1E2E3
if(responseCode>=400) 3 +BPqhzf
{ W&BwBp]K
processErrorCode(responseCode); FhAuTZk
return -2; //-2 represent access is error =5I1[p;
} 6DR@$fpt
_(J- MCY\
Pw hs`YGMF
String sHeader; j$&k;S
9BNAj-Xa
[WX+/pm7>
for(int i=1;;i++) X1#D}
{ {3`#? q^o'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B;hc|v{(
//Utility.log(in.readLine()); 0%`\8
sHeader=httpConnection.getHeaderFieldKey(i); f9&D0x?
if(sHeader!=null) Mwp#.du(
{ xgsD<3
if(sHeader.equals("Content-Length")) bq<QUw=]q&
{ "p2 $R*ie
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v#YO3nD
break; BAdHGwomh
} f(?>z!n0
} z`>a,X
else p^ 9QYR
break; JR'Q Th:z
} o9q%=/@,
} ~e,
catch(IOException e){e.printStackTrace ();} (3{'GX2c
catch(Exception e){e.printStackTrace ();} eey <:n/Z
yTkYPx
+7N6]pK|"
Utility.log(nFileLength); ZCbxL.fFz
!+9H=u
.I {X
return nFileLength; 3`IDm5
} L~I<y;x
Y?ZTl762
n?!.r c
//保存下载信息（文件指针位置） V|#B=W
private void write_nPos() Qaq{UW
{ b(;"p-^
try{ Y@M=6G
output = new DataOutputStream(new FileOutputStream(tmpFile)); REQ2pfk0
output.writeInt(nStartPos.length); Uu>YE0/)
for(int i=0;i<nStartPos.length;i++) f==o
{ ~9h6"0K!
// output.writeLong(nPos); XrFyN(p
output.writeLong(fileSplitterFetch.nStartPos); 2"yzrwZ:
output.writeLong(fileSplitterFetch.nEndPos); 7ABHgw~?8r
} Ud`V"X
output.close(); :4]&R9J>o
} u2JkPh&!rq
catch(IOException e){e.printStackTrace ();} X[h=UlF
catch(Exception e){e.printStackTrace ();} q|=tt(}G
} %zb7M%dC6`
6\OSIxJZF
&"Ua"H)
//读取保存的下载信息（文件指针位置） s3/->1#i
private void read_nPos() "*kWM
{ NAx( Qi3
try{ cS4e}\q,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ogip#$A}3
int nCount = input.readInt(); o=q N+-N
nStartPos = new long[nCount]; K34ca-~
nEndPos = new long[nCount]; ;# {XNq<1
for(int i=0;i<nStartPos.length;i++) [WY NA-O
{ J);1Tpm
nStartPos = input.readLong(); Rk2ZdNc\
nEndPos = input.readLong(); \EUc17
} \eI )(,A
input.close(); :==kC672
} #wx0xQ~,J
catch(IOException e){e.printStackTrace ();} l \xIGs
catch(Exception e){e.printStackTrace ();} 1nBE8 N
} rTDx|pvYx
[^1;8Tbk
kxThtjgv
private void processErrorCode(int nErrorCode) T7Lk4cU
{ 9n|H%AC
System.err.println("Error Code : " + nErrorCode); \P&'4y~PL
} EG7ki0
s/`4]B;2U
k-b_ <Tbo|
//停止文件下载 q<,?:g$k
public void siteStop() }1N)3~
{ `@")R-
bStop = true; o Ep\po1
for(int i=0;i<nStartPos.length;i++) =QRLKo#_
fileSplitterFetch.splitterStop(); pFGdm3pV
W{=>c/
5t:4%
} pc^(@eD
} Rj^bZ%t
//负责部分文件的抓取 ,yAvLY5P
**FileSplitterFetch.java Ga N4In[d
*/ |+x;18
package NetFox; HTf7r-
vRn^n
,5t.0XqS
import java.io.*; i\},
import java.net.*; H.O7Y
7 82NiVed
#u|;YC
public class FileSplitterFetch extends Thread { Z;7f D
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P[#V{%f*5
String sURL; //File URL SZ1+h TY7d
long nStartPos; //File Snippet Start Position :g+R}TR[i
long nEndPos; //File Snippet End Position p,]Hs{R
int nThreadID; //Thread's ID /_o1b_1U
boolean bDownOver = false; //Downing is over ~WR6rc
boolean bStop = false; //Stop identical afGb}8 Q9
FileAccessI fileAccessI = null; //File Access interface 9t7_7{Q+;
SobK<6
Fg5>CppH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {B\ar+9>
{ kpxd+w
this.sURL = sURL; )h2wwq0]
this.nStartPos = nStart; DE."XSni
this.nEndPos = nEnd; M!!W>A@T[g
nThreadID = id; ~?[%uGI0h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y5|`B(
} ~iEH?J%i1r
SZK~<@q5
@"'1"$
public void run() y?CEV-3+
{ C1)TEkc"C
while(nStartPos < nEndPos && !bStop) (`!?p ^>A
{ i,<TaW*I
#*}4=
l4L&hY^
try{ l')?w]|
URL url = new URL(sURL); 2+sNt6B2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &0Wv+2l@
httpConnection.setRequestProperty("User-Agent","NetFox"); H.|FEV@
String sProperty = "bytes="+nStartPos+"-"; H5^'J`0\
httpConnection.setRequestProperty("RANGE",sProperty); ^|>vK,q$I
Utility.log(sProperty); 3~a!h3.f
B~caHG1b
|DwI%%0(F
InputStream input = httpConnection.getInputStream(); sW3-JA]
//logResponseHead(httpConnection); +\\,FO_
S=eY`,'#R
~Q>97%
byte[] b = new byte[1024]; N/qr}- 3z
int nRead; |a3)U%rUEQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )z2Tm4>iql
{ nFX8:fZ$>
nStartPos += fileAccessI.write(b,0,nRead); \iSaxwU_
//if(nThreadID == 1) ]\sBl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FUvZMA$
} w# ,:L)
>9uDY+70I3
hi`\3B
Utility.log("Thread " + nThreadID + " is over!"); 7W5FHZd'
bDownOver = true; T&w3IKb|}
//nPos = fileAccessI.write (b,0,nRead); 4F)z-<-b
} .!l#z|/x
catch(Exception e){e.printStackTrace ();} \_De( p
} #wk'&XsC#z
} 6EGh8H f
zw7=:<z=
J0C,KU(
//打印回应的头信息 8`U5/!6fu
public void logResponseHead(HttpURLConnection con) $*9h\W-)`Q
{ Do=*bZ;A
for(int i=1;;i++) ,Hch->?Og
{ jF_K*:gQ
String header=con.getHeaderFieldKey(i); aVM@^n
if(header!=null) kbM4v G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {%N*AxkvId
Utility.log(header+" : "+con.getHeaderField(header)); |L%F`K>Z:
else Ke~a
break; Ip4CC'
} -KCm#!
} bo0m/hVU
j42U|CuK
) e;)9~
public void splitterStop() 5m=3{lBi
{ hz>&E,<8q
bStop = true; 6AUXYbK,
} XB50>??NE
iVFHr<zk
df&d+jY
} :G9.}VrU
T&tCXi
Tm.(gK
/* .B6$U>>NS^
**FileAccess.java _^0yE_ili
*//文件访问(定位，写) 5owUQg,W
package NetFox; Q/1 6D
import java.io.*; rgRh ySud
A+iQH1C0h
,fT5I6l
public class FileAccessI implements Serializable{ iRPt0?$
Q|"{<2"]U0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cPPE8}PVH
RandomAccessFile oSavedFile; '2WYbcU
long nPos; N|h`}*:x=
<q~&g &&+
@Vr?)_0
public FileAccessI() throws IOException Hh(_sewo
{ /=FQ{tLr
this("",0); zX"@QB3E
} DHaSBk
HZ>Xm6DnC5
+s V$s]U
public FileAccessI(String sName,long nPos) throws IOException I8Y[d$z
{ 2(\~z@g
oSavedFile = new RandomAccessFile(sName,"rw"); CGbW]D$@
this.nPos = nPos; vAy`8Q
oSavedFile.seek(nPos); :cnH@:
} "o*F$7D!
>wNE!Oa*B
L@_IGH
public synchronized int write(byte[] b,int nStart,int nLen) q-KN{y/
{ P2_JS]>
int n = -1; lo,?mj%M
try{ Q6`oo/
oSavedFile.write(b,nStart,nLen); ^;Nu\c
n = nLen; QNLkj`PL/
} |0vY'A)]
catch(IOException e) 2w$o;zz1
{ ^}ngbDn
e.printStackTrace (); b*no.eB
} gLaFIeF<+
l-Xxur5M'
`jSxq66L p
return n; pa~.[cBI
} B+ud-M0
$-|`#|CBd
VuN= JX
} &DYHkG
G[)Ll=
Ep|W>
/* aW$sd)
**SiteInfoBean.java ?i>.<IPOq
*/ )|~pocXt<
package NetFox; ~]*P/'-{#
j,K]TJ
x\]%TTps
public class SiteInfoBean { w`bojM@e1
nAZuA]p}S]
I:P/ ?-
private String sSiteURL; //Site's URL WtN o@e'
private String sFilePath; //Saved File's Path ;dPyhR
private String sFileName; //Saved File's Name q~^Jd=cB\
private int nSplitter; //Count of Splited Downloading File I8d#AVF2
XkHO=
oP$NTy[
public SiteInfoBean() X2 c<.
{//nSplitter的缺省值为5 9fp1*d
//default value of nSplitter is 5 [[}KCND
this("","","",5); Du k v[/60
} $z"3_4a
vrXUS9i.
%G1kkcdH<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6D_3Hwrs
{ g""1f%U_p
sSiteURL= sURL; +/'3=!oyd
sFilePath = sPath; <Td4 o&JR
sFileName = sName; )@Fuw*
this.nSplitter = nSpiltter; dE=4tqv-r
l~kxt2&
k_ 9gMO
} paF$o6\
v)mO"\
L=nyloz,0
public String getSSiteURL() GD<xmuo
{ sPuNwVX>}I
return sSiteURL; g]PmmK_L
} ?B3
N2[EdOJT_
KP`{ UD)
public void setSSiteURL(String value) 0"]N9N;/
{ -$WU-7`
sSiteURL = value; u;R<
} 7SOi9JU_
N=]2vyh
xPoI+,
public String getSFilePath() T2|dFKeWG
{ T~@$WM(
return sFilePath; M}2a/}4
} [}Vne;V
T{-<G13
=oz$uD}?
public void setSFilePath(String value) EUZ#o\6
{ oKjQ? 4
sFilePath = value; {,61V;Bpm
} fgcI55&jV{
!?!~8J~
P/uk]5H^
public String getSFileName() Wm_:1~
{ xV@/z5Tq
return sFileName; d;1%Ei3K
} Gzy"$t
y qDE|DIez
&!7{2E\7C
public void setSFileName(String value) Plpt7Pa_
{ ig|ol*~
sFileName = value; _ T ;+*
} =s3f{0G
JtA tG%
P?D;BAP2
public int getNSplitter() Hq=5/N
{ X.TsOoy
return nSplitter; N0TEVDsk
} (0Buo#I
)1f8 H,q^
C8 [W
public void setNSplitter(int nCount) h~|B/.[R:3
{ )w\E^
nSplitter = nCount; {Yp>h5nwM_
} it?l! ~
} 2eNA#^T=
RE~:+.eB
t0t" =(d
/* L9L!V"So1k
**Utility.java 2rK%fV53b
*/ 6%'bo`S#
package NetFox; |oCE7'BaP
-UD^O*U
}?^V9K-
public class Utility { ]7W!
, H$1iJ?
c~j")o
public Utility() ?8dd^iX/
{ 0V:7pSC{P
9cV;W\ Tw
!@2L g
} rO#WG}E<"
zW[fHa$m
//线程睡眠 ~%)ug3%e
public static void sleep(int nSecond) MBlhlMyI
{ ME'hN->c
try{ w=]id'`?q
Thread.sleep(nSecond); yffg_^fR
} @0js=3!2
catch(Exception e) 19V
{ H\W/;Nn
e.printStackTrace (); 9UF^h{X
} %=C49(/K_
} e6O+hC]:
!yxb=>A
//日志 k;aV4 0N9
public static void log(String sMsg) ZY NHVR
{ p%MH**A
System.err.println(sMsg); /"$A?}V
} ?"23XKe
+ Xc s<+b
VG,O+I'^z
public static void log(int sMsg) |Dz$OZP
{ ?;{d
System.err.println(sMsg); %qN_<W&Ze
} % Q| >t~
} o{C7V*
$_bhZnYp7
/da5"
/* ?f}lYQzM
**TestMethod.java POZ5W)F(
*/ W ='c+3O6
package NetFox; ;S,k U{F
L?[NXLn+
f9R~RRz
public class TestMethod { |ATz<"q>
WX2:c,%:
ey icMy`7{
public TestMethod() ="yN4+0-p
{ ///xx/weblogic60b2_win.exe m*'^*#
try{ "YW&,X5R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A:{PPjs%LA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <m") 2dJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?\_\pa/+
fileFetch.start(); }cl~Vo-mp
} eN]AJ%Ig
catch(Exception e){e.printStackTrace ();} 8 K7.; t1
rUg<(/c
nDiy[Y-4Wp
} ! };OLQ
@jXdQY%{
jY: )W*TXt
public static void main(String[] args) uL.)+E
{ ]Tv0+ Ao
new TestMethod(); S!\4,6
} 6oh\#v3zV
} r8]y1 Om<
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