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)); p-=+i
} 4$=Dq$4z
for(int i=0;i<nEndPos.length-1;i++) hYS*J908
{ 8tM40/U$
nEndPos = nStartPos[i+1]; 72gQ<Si
} 0"~`U.k~M
nEndPos[nEndPos.length-1] = nFileLength; h] (BTb#-
} tnbtfG;z#
} :n:Gr?
KMxP%dV/=
Sn\S`D
//启动子线程 HrUQ X4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H h4G3h0
for(int i=0;i<nStartPos.length;i++) pr2b<(Pm
{ TS9=A1J#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >4A~?=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5Mfs)a4j.
nStartPos,nEndPos,i); &VIX?UngE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f((pRP
fileSplitterFetch.start(); 2l)J,z
} lD;="b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wL'tGAv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (GVH#}uB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g7*ii X
nEndPos = " + nFileLength); nwk66o:|
// fileSplitterFetch[nPos.length-1].start(); P&@:''
{ jnQoxN
8#OcrJzC
//等待子线程结束 1sL#XB$@N
//int count = 0; cSYW)c|t
//是否结束while循环 J`T1 88
boolean breakWhile = false; Y"GU"n~
}s_'q~R
aI$D qnF4
while(!bStop) 9]AiaV9
{ ffuV158a&
write_nPos(); x&6SjlDb$K
Utility.sleep(500); ceakTAB[
breakWhile = true; N;XaK+_2F
D"WqJcDt
y$VYWcFE
for(int i=0;i<nStartPos.length;i++) 1]HEwTT/1_
{ $2uZdl8Rvj
if(!fileSplitterFetch.bDownOver) V6.xp{[
{ uqy b
breakWhile = false; 7tOOruiC
break; W+[XNIg5
} ?)$+W+vK
} ,EyZ2`|
if(breakWhile) En:.U9?X
break; =yv_i]9AN
j?&Rf,,%
Ys@M1o
//count++; bi:m;R
//if(count>4) E5d?toZ,8"
// siteStop(); bT|NZ!V
} " gB.
,Vz 1l_7
|1GR:b24
System.err.println("文件下载结束！"); 'JR2@W`]]
} 2ZMYA=[!
catch(Exception e){e.printStackTrace ();} p@H]F<
} wYtL1D(
6fvzTd},
l MCoc'ae
//获得文件长度 c[:OK9TH
public long getFileSize() yvxdl=s
{ HC0q_%j
int nFileLength = -1; 3.q%?S}*
try{ CmaV>
URL url = new URL(siteInfoBean.getSSiteURL()); O)ks
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ueO&%
httpConnection.setRequestProperty("User-Agent","NetFox"); 5Xn+cw*
V[f-Nj Kf
Kq}/`P
int responseCode=httpConnection.getResponseCode(); n:zoN2lC
if(responseCode>=400) S<"M5e
{ 1O bxQ_x
processErrorCode(responseCode); J/3qJst
return -2; //-2 represent access is error E#t;G:+A
} ncg5%(2
p[BF4h{E
Nx~9Ug
String sHeader; ^06f\7A
3F'{JP
a!MhxM5
for(int i=1;;i++) KlMrM% ;y
{ #3@ Du(_n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k9j_#\E[
//Utility.log(in.readLine()); iOpMU
sHeader=httpConnection.getHeaderFieldKey(i); _@CY_`a
if(sHeader!=null) {9sA'5
{ c$),/0td|
if(sHeader.equals("Content-Length")) ea3;1-b:
{ %,$Ms?,n`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h^klP:Q
break; l2uh"!
} qd*3| O^
} -x~h.s,
else O$jj&
break; * z|i{=W F
} E~?0Yrm F
} ~[|&)}q
catch(IOException e){e.printStackTrace ();} NNZ%jJy?=,
catch(Exception e){e.printStackTrace ();} sBP.P7u
y6.}h9~
j.Ro(0%
Utility.log(nFileLength); Le3H!9lbc
SH>L3@Za
}ge~Nu>w
return nFileLength; 9{{QdN8
} hn9'M!*:O
Gt4| ]
;V(- ;O
//保存下载信息（文件指针位置） )%rGD =2~
private void write_nPos() XMb]&VvH
{ bJc<FL<E
try{ K_/8MLJQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); >|%dN jf@Q
output.writeInt(nStartPos.length); g_lj/u]P
for(int i=0;i<nStartPos.length;i++) P7GuFn/p~2
{ _2Sb?]Xn
// output.writeLong(nPos); YXE?b@W"
output.writeLong(fileSplitterFetch.nStartPos); j^ L"l;m
output.writeLong(fileSplitterFetch.nEndPos); #m_3ls}W$
} ~!( (?8"
output.close(); C/Vs+aW n
} om%L>zfB
catch(IOException e){e.printStackTrace ();} KL:x!GsV5e
catch(Exception e){e.printStackTrace ();} r[xj,eIb
} 4yhan/zA
^):m^w.
<CrNDY
//读取保存的下载信息（文件指针位置） 9kmEg$WM
private void read_nPos() uC{qaMQ
{ *_G(*yAe(
try{ {)j~5m.,/o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e~#;ux
int nCount = input.readInt(); I&9_F%rX
nStartPos = new long[nCount]; N{L'Q0!
nEndPos = new long[nCount]; rQ~7BlE
for(int i=0;i<nStartPos.length;i++) @tQu3Rq@
{ l,cnMr^.W
nStartPos = input.readLong(); lJaR,,
nEndPos = input.readLong(); zTtn`j$
} npsDy&
input.close(); ~JjL411pG
} 5,/rh,?
catch(IOException e){e.printStackTrace ();} A-5xgp,
catch(Exception e){e.printStackTrace ();} x*}41;j}C
} yW::`
^)$(Fe<
;Du+C%
private void processErrorCode(int nErrorCode) p,_,o3@~
{ Y+il>.Z
System.err.println("Error Code : " + nErrorCode); "B18|#v
} Z(Styn/x
~s.~X5
)xJCH9h
//停止文件下载 ?:@13wm
public void siteStop() "R8:s
{ ZAe'lgS
bStop = true; 5^kLNNum
for(int i=0;i<nStartPos.length;i++) b1rW0}A
fileSplitterFetch.splitterStop(); a%\6L
<sU?q<MC
Q-A:0F&{t
} m|K"I3W$
} GYvD*?uBc
//负责部分文件的抓取 _+c' z
**FileSplitterFetch.java MW^(
*/ zKRt\;PW
package NetFox; Fjnp0:p9X
t:MeSO
%:yp>nm
import java.io.*; &j}08aK%
import java.net.*; <x&0a$I
12{F
a1^CpeG~
public class FileSplitterFetch extends Thread { d|I_SI1
"LwLTPC2
n6AN
String sURL; //File URL KGM9 b
long nStartPos; //File Snippet Start Position |3LD"!rEx
long nEndPos; //File Snippet End Position &,v-AL$:Q
int nThreadID; //Thread's ID W=E+/ZvPt
boolean bDownOver = false; //Downing is over X`/GiYTu
boolean bStop = false; //Stop identical pm2-F]
FileAccessI fileAccessI = null; //File Access interface %@L[=\ 9
[j3-a4Wu
{oXU)9vj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fyt ODsb>
{ C8{bqmlm@
this.sURL = sURL; $7bLw)7
this.nStartPos = nStart; % w\
this.nEndPos = nEnd; WdWMZh
nThreadID = id; q?R^~r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x3>ZO.Q
} &7\=Jw7w
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!+UU[uM
public void run() ^`~s#L7
{ /"+CH\) E
while(nStartPos < nEndPos && !bStop) ='W=
{ 64LX[8Ax#
\T'.b93~B
-1_WE/Ps
try{ 1'NJ[ C`
URL url = new URL(sURL); %`EyG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *&vlfH
httpConnection.setRequestProperty("User-Agent","NetFox"); f:9bq}vH
String sProperty = "bytes="+nStartPos+"-"; I`~Giz7@
httpConnection.setRequestProperty("RANGE",sProperty); c>|1%}"?
Utility.log(sProperty); @$Xl*WT7
12i<b
L[s`8u<_)z
InputStream input = httpConnection.getInputStream(); adcH3rV
//logResponseHead(httpConnection); @~z4GTF9i
{xD\w^
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byte[] b = new byte[1024]; bJ"}-s+Dx
int nRead; _4f=\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G$^u2wz.
{ b FMBIA|
nStartPos += fileAccessI.write(b,0,nRead); Z<jC,r
//if(nThreadID == 1) *V`E)maU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B,q)<z6<
} s||c#+j"8
u?F^gIw
j].=,M<dxE
Utility.log("Thread " + nThreadID + " is over!"); %ws@t"aER
bDownOver = true; mP]a}[
//nPos = fileAccessI.write (b,0,nRead); ,/YTW@N
} qOTo p-
catch(Exception e){e.printStackTrace ();} {/|tVc63
} zNO,vR[\
} xrZzfg
/u&7!>,
o(gV;>I
//打印回应的头信息 [ KDNKK
public void logResponseHead(HttpURLConnection con) O@>ZYA%
{ >g;995tG
for(int i=1;;i++) v@d]*TG
{ ]&?8l:3-G
String header=con.getHeaderFieldKey(i); K8JshFIe
if(header!=null) arc{:u.K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uC! dy
Utility.log(header+" : "+con.getHeaderField(header)); Y<t(m$s
else `)tIXMn
break; O9*l6^Scw
} >rYkVlv
} 6VtN4c.Q
)&$mFwf
)!lx'>0>
public void splitterStop() 'si{6t|
{ 2BO&OX|X
bStop = true; iOtf7.@
} Os/?iGlD*E
d/[kky}
} 4ZWAzH
} tZY6{,K%4
< w;490g
25;(`Td5
/* ]2c0?f*Y7
**FileAccess.java L1kAAR
*//文件访问(定位，写) b"nD5r
package NetFox; +*IRI/KUD
import java.io.*; K@vU_x0Sl
/bF>cpM
c=D~hzN
public class FileAccessI implements Serializable{ yUN>mD-
(K('@W%\?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q<K/q"0-l
RandomAccessFile oSavedFile; ovZ!}
long nPos; xKkXr-yb`f
}S;A%gYm
Svdmg D!
public FileAccessI() throws IOException 30O7u3Zrb
{ y@<&A~Cl^
this("",0); #itZ~tol
} V@nZ_.
('2Z&5
,'n`]@0?\
public FileAccessI(String sName,long nPos) throws IOException |-HNHUF
{ KV! (
oSavedFile = new RandomAccessFile(sName,"rw"); WtC&Qyuq
this.nPos = nPos; z0UtKE^b
oSavedFile.seek(nPos); *;F:6p4_
} #8$"84&N.
e|q~t {=9S
J06D_'{
public synchronized int write(byte[] b,int nStart,int nLen) >uYU_/y$2
{ hrGX65>
int n = -1; !;K zR&
try{ {&a6<y#-
oSavedFile.write(b,nStart,nLen); DPkH:X
n = nLen; xUTTRJ(\
} {w@9\LsU
catch(IOException e) D^}2ilk!
{ P&yB(M-z
e.printStackTrace (); +.gj/uy*
} /!N=@z)
ZZ T 9t#~
/&9R*xNST#
return n; ^9><qKbO
} X]o"vx%C
!L<z(dV|(
Gzs$0Ki=
} r7^v@
K &%8w
n}- _fx
/* 8A}<-?>
**SiteInfoBean.java "xnULQK
*/ 7-0j8$`
package NetFox; C{+JrHV%h
P#V}l'j(<a
QMy1!:Z&!
public class SiteInfoBean { 5tk7H2K^<
/,~g"y.;,
skU }BUK6
private String sSiteURL; //Site's URL 4dm0:, G
private String sFilePath; //Saved File's Path 0{I-x^FI
private String sFileName; //Saved File's Name )1YX+',"
private int nSplitter; //Count of Splited Downloading File VGc.yM)& j
itg"dGDk
jeB"j
public SiteInfoBean() MTq/
{//nSplitter的缺省值为5 Yh Ow0 x
//default value of nSplitter is 5 m77!i>V)
this("","","",5); G_zK .N
} .*X=[" F
g)!q4 -q
Vol}wc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;/kmV~KG
{ eNO[ikm
sSiteURL= sURL; !Rgj'{
sFilePath = sPath; -s1.v$g
sFileName = sName; i29a1nD4Hm
this.nSplitter = nSpiltter; 9p1@Lfbj
>&k`NXS|V
B79~-,Yh
} KXpbee
o,S(;6pDJ
%$'fq*8b
public String getSSiteURL() $*LBZcL
{ sZ7~AJ
return sSiteURL; j)#yyK{k2s
} 7j29wvSp5
z@ `u$D$n
hm k ~
public void setSSiteURL(String value) [_}8Vv&6
{ Rf2mBjJ(z
sSiteURL = value; /a9CqK
} C7f*Q[
%|1s9?h7\
id" l"
public String getSFilePath() ?YUL~P
{ VDZOJM)(
return sFilePath; ]EUQMyR
} vp9wRGd
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lR9uD9Dr
public void setSFilePath(String value) n,LM"N:
{ e Qk5:{[
sFilePath = value; ?RW1%+[
} DrbjklcUU
$o9@ ?2
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public String getSFileName() ^~6gkS }
{ iq^;csyKb
return sFileName; Koj9]2<0
} p L^3*B.Nr
`M. I.Z_
%<'.c9u5
public void setSFileName(String value) 6eA)d#
{ I6gduvkXi4
sFileName = value; YpRhl(|
} GV28&!4sS
p)]x,F
& JJ*?Dl
public int getNSplitter() _ n1:v~
{ shP}T[<
return nSplitter; x9S9%JG :
} ?;.=o?e9
@A<~bod
JfK4|{@
public void setNSplitter(int nCount) SU6Aq?`@
{ ^HtB!Xc
nSplitter = nCount; Pl-9FLJ
} "WO0rh`
} ?STO#<a
MZB}O" r
{`T^&bk
/* ,nGQVb
**Utility.java TtKKU4yp
*/ -_eG/o=M
package NetFox; $<Y%4LI
OdNcuiLa
Zm7,O8
public class Utility { [1ClZ~f
m{~L Fhhd1
m~fDDQs
public Utility() pn){v
{ mEkYT
w`3.wALb
N93R(x)%
} xU6dRjYhH9
TeO'E<@
//线程睡眠 K5\l (BB
public static void sleep(int nSecond) UO!} 0'
{ e$JCak=
try{ zr_L V_e
Thread.sleep(nSecond); &A`,hF8
} Y(2Z<d
catch(Exception e) Jf\`?g3#
{ (0.JoeA`y
e.printStackTrace (); R*XZPzg%
} yF%e)6
} Q<ia
bZK^q B
//日志 pjFj{
public static void log(String sMsg) @Y>PtA&w*
{ 0vBQzM Q
System.err.println(sMsg); H*P+>j&
} Zk>m!F>,p
a/3'!}&e
t~nW&]E
public static void log(int sMsg) %+;l|Z{Uf
{ 5,V*aP
System.err.println(sMsg); "r3h+(5
} 3bjCa\ "
} 2Vu?Y
9 `q(_\x
mFxt +\
/* H~SU:B:
**TestMethod.java D ] n|d+
*/ U>m{B|H
package NetFox; ]=I2:Rb
,dw\y/dn
{;zHkmx
public class TestMethod { o@]n<ZYo
_x#y
bAuiMw7!
public TestMethod() V[kn'QkWv
{ ///xx/weblogic60b2_win.exe 0uPcEpIA
try{ +7nvy^m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aGsO~ODc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s{V&vRr
SiteFileFetch fileFetch = new SiteFileFetch(bean); a|#pl!
fileFetch.start(); nn$^iw`
} ,j\uvi(Y
catch(Exception e){e.printStackTrace ();} v0tFU!Q%
dLwP7#r
8*&73cp
} ) LTV+?
ko'V8r`V
8}4.x3uw
public static void main(String[] args) jVN=_Y}\
{ ?hR0 MnP
new TestMethod(); 8m `Y
} aG4 ^xOD
} \Cin%S.C
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