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)); 85H8`YwPh
} `qr[0wM
for(int i=0;i<nEndPos.length-1;i++) `FmI?:Cv
{ LiN{^g^fx
nEndPos = nStartPos[i+1]; e`C'5`d]
} KU$.m3A>
nEndPos[nEndPos.length-1] = nFileLength; O(!wDnhc
} }l_) d
} IJ=~hBI
G>H&M#7K
2TIZltFS0e
//启动子线程 O'j;"l~H|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lRentNg0b
for(int i=0;i<nStartPos.length;i++) OcIJT1
{ C>j"Ck^<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ip<STz]-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C' ny 2>uA
nStartPos,nEndPos,i); 3+(Fq5I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;O.U-s
fileSplitterFetch.start(); F lbL`@4M
} uTn(fs)D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Bz]64/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?hmj0i;XC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S .1~#
nEndPos = " + nFileLength); 7gPkg63
// fileSplitterFetch[nPos.length-1].start(); f<y""0L9
LN_6>u
UWmWouA
//等待子线程结束 .dl1sv U
//int count = 0; N?R1;|Z]
//是否结束while循环 +EkZyM~z2
boolean breakWhile = false; Cee?%NaTS
2j(w*k q~
0M:.Jhp
while(!bStop) _DH,$evS%
{ *I>1O*
write_nPos(); t;ggc{
Utility.sleep(500); ~6{;3"^<
breakWhile = true; 2<|+h= &
&]uhPx/
|'1[\<MM3
for(int i=0;i<nStartPos.length;i++) V#5BZU-
{ !3d+"tL S
if(!fileSplitterFetch.bDownOver) +&Sf$t 1
{ J/ <[irC
breakWhile = false; He&dVP
break; e7 5*84
} |67<h5Q1
} 2hu;N
if(breakWhile) piY=(y&3
break; mp!6MOQ
/GfC/)1_
+9,"ne1'e
//count++; 64`V+Hd
//if(count>4) NDCZc_
// siteStop(); xZbm,.v
} Oh-HfJyi
jjEkz 5
%w_h8
System.err.println("文件下载结束！"); [ @&
} B9Y "J
catch(Exception e){e.printStackTrace ();} LlX 7g_!
} 7S1 Y)
EC&w9:R
o= N=W
//获得文件长度 }-YD_Pm K-
public long getFileSize() ="<+^$7:k
{ EZE/~$`3
int nFileLength = -1; )\'U$
try{ KS3 /
URL url = new URL(siteInfoBean.getSSiteURL()); fg+Q7'*Vq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h#'(UZ
httpConnection.setRequestProperty("User-Agent","NetFox"); fMI4'.Od
,W7\AY07]
ES}@mO
int responseCode=httpConnection.getResponseCode(); xgnt)&7T
if(responseCode>=400) doVBVTk^
{ 1k3wBc5<
processErrorCode(responseCode); 69TQHJ[
return -2; //-2 represent access is error mEr*n
} \0'o*nlJ
d,6 Z
xSug-
String sHeader; HE7JQP!q
N1zB;-0t
f-tjMa /_
for(int i=1;;i++) 0:Yz'k5
{ `lqMifD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fp|b@
//Utility.log(in.readLine()); U}_l]gNn
sHeader=httpConnection.getHeaderFieldKey(i); JrQ*.lJj
if(sHeader!=null) w*uHB;?
{ _<=U.T`
if(sHeader.equals("Content-Length")) 8s6[?=nM
{ >A7),6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w91{''sK
break; t8E'd:pE
} wJ/k\
} (Lo<3a-]
else J`Q#p%W
break; 6Z\[{S];
} ,3!l'|0jJ
} ''s]6Jjw
catch(IOException e){e.printStackTrace ();} oJvF)d@gU
catch(Exception e){e.printStackTrace ();} %o.{h
d_-{-@
*ukE"Aj
Utility.log(nFileLength); ~^UQw?;
6~ev5SD;f
66,?f<b
return nFileLength; g0 \c
} C(Yk-7
OAEJ?ik
hS OAjS
//保存下载信息（文件指针位置） 6(f[<V!r
private void write_nPos() q UY;CEf
{ W1w)SS
try{ BVC{Zq6hi
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0OMyE9jJJ
output.writeInt(nStartPos.length); xUD$i?3z
for(int i=0;i<nStartPos.length;i++) F*d{<
{ `<>8tZS9"
// output.writeLong(nPos); A{E0 a:v
output.writeLong(fileSplitterFetch.nStartPos); Y4Z?`TL
output.writeLong(fileSplitterFetch.nEndPos); 1Nk}W!v
} (t9qwSS8z
output.close(); Tj{!Fx^H
} 'ej{B0rE
catch(IOException e){e.printStackTrace ();} >~$ S!
catch(Exception e){e.printStackTrace ();} .6E7 R
} AMYoSc
A_%}kt (6
t@/r1u|iq
//读取保存的下载信息（文件指针位置） 5Wi5`8m
private void read_nPos() ]~(Ipz2NP
{ ZH%[wQ~4
try{ =fHt|}.K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cuR|cUK
int nCount = input.readInt(); &T}v1c7)
nStartPos = new long[nCount]; U<r<$K
nEndPos = new long[nCount]; &fj&UBA
for(int i=0;i<nStartPos.length;i++) &K^h'>t'
{ o\Hg2^YY>
nStartPos = input.readLong(); _}!Q4K
nEndPos = input.readLong(); j<+iL]b
} .@APxeU
input.close(); "MXd!
} )}c$n
catch(IOException e){e.printStackTrace ();} +X;6%O;
catch(Exception e){e.printStackTrace ();} ]'_z(s}
} L#u6_`XJ+
RkLH}`#
XR\ iQ
private void processErrorCode(int nErrorCode) hBE}?J>
{ <UQ:1W8>B
System.err.println("Error Code : " + nErrorCode); (7ew&u\Li
} eOn,`B1
fD\h5`-
df1* [
//停止文件下载 u(ZS sftat
public void siteStop() 1"odkM
{ BJj~fNm1Zr
bStop = true; 3 XfXMVm
for(int i=0;i<nStartPos.length;i++) }C#YR(]
fileSplitterFetch.splitterStop(); 6w}:w?=6
jd2Fh):q
m2|0<P@k!
} !gf&l ^)
} 'KQuz)-
//负责部分文件的抓取 g\(7z P
**FileSplitterFetch.java VY _(0
*/ hkU# lt
package NetFox; Ky nZzR
(I[o;0w
t41cl
import java.io.*; _i8$!b2Mr
import java.net.*; ,(`@ZFp$
RL&3 P@r
%q*U[vv
public class FileSplitterFetch extends Thread { nLtP^ 1~9H
cR5<.$aY
KH KqE6
String sURL; //File URL &`TX4b^/!
long nStartPos; //File Snippet Start Position =_yOX=g|
long nEndPos; //File Snippet End Position N%B#f\N
int nThreadID; //Thread's ID <O>Q;}>gfc
boolean bDownOver = false; //Downing is over Zo0&<QWj
boolean bStop = false; //Stop identical ,XA;S5FE
FileAccessI fileAccessI = null; //File Access interface Pm?6]] 7
,+X8?9v
c~RIl5j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >M1/m=a
{ II<<-Y6
this.sURL = sURL; fRa1m?%s
this.nStartPos = nStart; p[uwG31IL`
this.nEndPos = nEnd; E?XA/z !
nThreadID = id; D9LwYftZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xj/X.
} g(5s{njL
Oy|9po
lHGv:TN
public void run() Xj-3C[8@
{ \:=Phbn
while(nStartPos < nEndPos && !bStop) Sej$x)Q\t
{ ;OKQP~^iH2
,Xh4(Gn#b
.M! (|KE4
try{ i5n'f6C
URL url = new URL(sURL); QHM39Eu]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ./g0T{&
httpConnection.setRequestProperty("User-Agent","NetFox"); kv5Qxj}
String sProperty = "bytes="+nStartPos+"-"; S$H4xkKs
httpConnection.setRequestProperty("RANGE",sProperty); Qp=uiXs
Utility.log(sProperty); cn\_;TYiJ
%eah=e
lT:<ZQyjT
InputStream input = httpConnection.getInputStream(); rzTyHK[
//logResponseHead(httpConnection); 3?geJlD4
7]v-2 *
wM&G-~9ujk
byte[] b = new byte[1024]; fzKKK+
int nRead; YT:1=Nf}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ci*5E$+\
{ x9ws@=[:
nStartPos += fileAccessI.write(b,0,nRead); 0?:ZERv
//if(nThreadID == 1) -Qgfo|po
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eQLa.0
} ^4fkZh
|-|BM'Y
?eO|s5r
Utility.log("Thread " + nThreadID + " is over!"); an7N<-?
bDownOver = true; X%-4x
//nPos = fileAccessI.write (b,0,nRead); ?SAi tQ3
} 7RLh#D|
catch(Exception e){e.printStackTrace ();} *= 71/&B
} m,KY_1%M
} hB.dqv]^
Kq?7#,_
B%pvk.`
//打印回应的头信息 ))F.|w
public void logResponseHead(HttpURLConnection con) 1,QRfckks
{ _SaK]7}m!
for(int i=1;;i++) f/B--jq
{ h>/ViB@"W|
String header=con.getHeaderFieldKey(i); !+6l.`2WI
if(header!=null) ,J^Op
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eXd(R>Mx
Utility.log(header+" : "+con.getHeaderField(header)); R3PhKdQ"
else st2>e1vg
break; Jc)1}
} _e3'f:
} }B-A*TI<h
U)!AH^{32
W% [5~N
public void splitterStop() ts]7 + 6V
{ GN<I|mGLJK
bStop = true; w}0Qy
} JK(&E{80
-AT@M1K7%
hvyN8We
} 6!nb)auVi
D:(f"
b{rmxtx
/* ttnXEF
**FileAccess.java 7|-xM>L$A
*//文件访问(定位，写) D$cMPFa2Nt
package NetFox; h 3&:"*A2
import java.io.*; @nP}q!y
Ic K=E]p
2YKM9Ks
public class FileAccessI implements Serializable{ O[y`'z;C
}dUC^04
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uKy*N*}
RandomAccessFile oSavedFile; O+?zn:
long nPos; |S{P`)z%f
[,^dM:E/
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public FileAccessI() throws IOException {1aAm+
{ !yX<v%>_0
this("",0); ~8(X@~Tn*
} ^-u HdafP
#sU~fq
Wp}9%Mq~Jy
public FileAccessI(String sName,long nPos) throws IOException ]$*{<
{ aT#{t{gkA
oSavedFile = new RandomAccessFile(sName,"rw"); eC?/l*gF3
this.nPos = nPos; *\KMkx
oSavedFile.seek(nPos); nnL$m_K~
} uV_)JZW,L
q7&yb.<KD.
7;'.5,-3c
public synchronized int write(byte[] b,int nStart,int nLen) 9K46>_TyH
{ =t$mbI
int n = -1; i?>> 9f@F
try{ Kxc$wN<
oSavedFile.write(b,nStart,nLen); 2ZbY|8X$r
n = nLen; o:8S$F`O@
} R}wwC[{
catch(IOException e) ckN(`W,xp
{ #IaBl?}r^
e.printStackTrace (); o+-Ge J
} C.eV|rc@T
l~4e2xoT
QP5:M!O<)
return n; l8xd73D)8
} wYQ1Z
i %hn
+%}5{lu_e
} ]2\2/~l
qa$[L@h>
EkStb#
/* M-Z6TL
**SiteInfoBean.java GQ-e$D@SfB
*/ t6bWSz0
package NetFox; Gj7QGIKx
hw ;dm
e,#+Xx0M
public class SiteInfoBean { [wy3Ld
|T$a+lHMD
O5TK&j
private String sSiteURL; //Site's URL fb0T/JTw
private String sFilePath; //Saved File's Path Eo {1y
private String sFileName; //Saved File's Name GrLM${G
private int nSplitter; //Count of Splited Downloading File &FJU%tFA
@8M'<tr<z
yToT7 X7F7
public SiteInfoBean() D)*_{
{//nSplitter的缺省值为5 a(x.{}uG,
//default value of nSplitter is 5 yA!3XUi
this("","","",5); 5gc:Y`7t
} dWW-tHv#
^b"x|8
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kKxL04
{ c+E//X|
sSiteURL= sURL; } Jdh^t.
sFilePath = sPath; r>@ B+Xi
sFileName = sName; de=5=>P7
this.nSplitter = nSpiltter; w>z8c3Dq}
x;ERRK
$vgmoJ@X0
} =0C l
, `[Z`SUk`
Qe @A5#
public String getSSiteURL() =e-a&Ep-z
{ Ersr\ZB
return sSiteURL; (sV]UGrZ
} j#LV7@H.e?
D y`W5_xSz
B7Ki@)
public void setSSiteURL(String value) ]|C_`,ux
{ 1*!c X
sSiteURL = value; 0,1L e$)6
} @wYQLZ
PEX26==
_q$0lqq~u
public String getSFilePath() %2@ Tj}xa
{ |z!q r}i
return sFilePath; Q QsVIHA
} {UX"Epd);n
5bF9IH
]689Q%D
public void setSFilePath(String value) H7z>S G0
{ AQnJxIL:
sFilePath = value; z&C{8aQ'
} -(/2_&"
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c]s(u+i
public String getSFileName() c ,h.`~{
{ O:`GL1{ve?
return sFileName; RQj`9F
} xVsa,EX b
LT,iS)dY+
*/%$6s~
public void setSFileName(String value) ~4MtDf
{ g( ]b\rj
sFileName = value; 8Z9MD<RLw
} ~h>rskJ_
"fX_gN?
hV3,^#9o
public int getNSplitter() [Vrc:%Jk
{ ;-3h~k
return nSplitter; '|YtNhWZ?
} V9+xL 1U#
`YFkY^T
p/ziFpU
public void setNSplitter(int nCount) Z-4K?;g'k
{ U7nsMD
nSplitter = nCount; iN:G/ss4O
} a^RZsR
} ^#a#<8Jz
K?h[.`}
|Q5H9<*
/* c0!Te'?
**Utility.java $Qn&jI38
*/ S2koXg(
package NetFox; C$]5l;`
bh=\
KcIc'G 9
public class Utility { "_nX5J9
)x$!K[=
IT8B~I\OY
public Utility() JiKImz
{ ?~F]@2)5w
hVlyEsLg
,DE(5iDS
} !&@2
NJ >I%u*
//线程睡眠 y\[L?Rmd
public static void sleep(int nSecond) fdd~e52f
{ re7!p(W?,
try{ =L:[cIRrT;
Thread.sleep(nSecond); bZxv/\
} cNdu.c[@
catch(Exception e) x2sN\tOh^
{ r`?&m3IOP
e.printStackTrace (); fy9uLl}h
} ILNE 4n
} 91BY]N
V78Mq:7d
//日志 K3La9O)>
public static void log(String sMsg) G"}qV%"6"
{ )URwIe{
System.err.println(sMsg); Sq?,C&LsA
} g* %bzfk=|
}%_qx|(P|t
HTxB=Q|
public static void log(int sMsg) O:2 #_
{ Tsu\oJ[
System.err.println(sMsg); b21}49bHN
} k"t>He
} C,[L/!
P~&O4['<
TLy;4R2Nn
/* &q.)2o#Q.
**TestMethod.java mG X\wta
*/ P<8LAc$T
package NetFox; yxqTm%?y
wyp{KIV
STv(kQs
public class TestMethod { \{kHSV%z
EH(tUwY%{
FSv1X
public TestMethod() %cS#+aK6M'
{ ///xx/weblogic60b2_win.exe aWdUuid
try{ nZe\5`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AmZuo_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MdLj,1_T
SiteFileFetch fileFetch = new SiteFileFetch(bean); R j-jAH
fileFetch.start(); m^z,,t9
} /;+oz
catch(Exception e){e.printStackTrace ();} `Rrr>vj
0"hiCGm'
Ec+22X
} ?.8<-
q5!0\o:
/\~l1.6`
public static void main(String[] args) R;%^j=Q
{ NOV.Bs{ yL
new TestMethod(); 8:~b &>
} miPmpu!
} 8`a,D5U:
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