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)); 56hA]O29O
} *]JdHO
for(int i=0;i<nEndPos.length-1;i++) 7t9c7HLuj/
{ h;lirvO|
nEndPos = nStartPos[i+1]; W\f9jfD
} avp;*G}
nEndPos[nEndPos.length-1] = nFileLength; dMx4ykrR
} 4;`Bj:.
} j\RpO'+}
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a'\By?V]
//启动子线程 ')S;[=v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vhr+g 'tf
for(int i=0;i<nStartPos.length;i++) }G$]LWgQx
{ yz+, gLY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~#\i!I;RY}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6pE :A@
nStartPos,nEndPos,i); ^0W(hA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 52zGJ I*
fileSplitterFetch.start(); zm9TvoC%}
} CBf7]n0H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CLKov\U\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CGw--`#\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pO<-.,
nEndPos = " + nFileLength); 6)\dBOz
// fileSplitterFetch[nPos.length-1].start(); mxwdugr`
"HM{b?N
OEr:xK2T
//等待子线程结束 Q4s&E\}
//int count = 0; O gmO&cE
//是否结束while循环 8|twV35
boolean breakWhile = false; NkxCs
tNs~M4TVVH
&K^MNd
while(!bStop) `P+(&taT
{ 0JRD
write_nPos(); 9+YD!y
Utility.sleep(500); 5H,G-
breakWhile = true; M ixwK,
>zY \Llv
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for(int i=0;i<nStartPos.length;i++) wN37zPnV~
{ ;@ WV-bLe
if(!fileSplitterFetch.bDownOver) WKA'=,`v
{ D 7shiv|,
breakWhile = false; J3S&3+2G
break; r0m)j
} 5CJZw3q
} vd#,DU=p!
if(breakWhile) 2>S~I"o0
break; ?3sT"r_d@
MWuXI1
Y ?]G}5
//count++; HW=xvA+
//if(count>4) "C%!8`K{a*
// siteStop(); D1,O:+[;.
} Kn+=lCk
;i#LIHJ
\9)[#Ld
System.err.println("文件下载结束！"); Mj0Cat=
} p}]q d4j
catch(Exception e){e.printStackTrace ();} >',y
} }F`beoMAkM
<l\N|+7R
@kngI7=E
//获得文件长度 1TqF6`;+
public long getFileSize() FyD.>ot7M
{ TW`mxj_J2
int nFileLength = -1; 2]jPv0u
try{ mp`PE=
URL url = new URL(siteInfoBean.getSSiteURL()); O{KB0"s>i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <Mgf]v.QS
httpConnection.setRequestProperty("User-Agent","NetFox"); ~] =?b)B
((3t:
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int responseCode=httpConnection.getResponseCode(); vW.%[]
if(responseCode>=400) Oo%!>!Lt,
{ 3 %(Y$8U
processErrorCode(responseCode); AfWl6a?T8:
return -2; //-2 represent access is error rFag@Z"["
} #!!AbuhzK{
K, (65>86;
993d/z|DX
String sHeader; Mps *}9
i|2$8G3
'ND36jHcRD
for(int i=1;;i++) FuP}Kec
{ m% bE-#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #0MK(Ut/
//Utility.log(in.readLine()); `6 Y33bQ
sHeader=httpConnection.getHeaderFieldKey(i); xcSR{IZ
if(sHeader!=null) `ENP=kL(+
{ ./maY1>T
if(sHeader.equals("Content-Length")) lC9S\s
{ I{n;4?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jW5iqU"{*
break; p?myuNd[
} q@Kk\m
} o<4D=.g7D
else y/4ny,s"
break; WEa>)@
} Md9l+[@
} Fn,k!q
catch(IOException e){e.printStackTrace ();} vnsSy33K
catch(Exception e){e.printStackTrace ();} (DJvi6\H
>a]t<
' Js?N
Utility.log(nFileLength); eOrYa3hQ
CM 9P"-
J~J@ ]5/
return nFileLength; 7Jx%JgF
} )*[ ""&
.)ST[G]WK
O<`R~
//保存下载信息（文件指针位置） &telCg:
private void write_nPos() Dr'sIH^
{ [,7-w
try{ ('WY5Yps
output = new DataOutputStream(new FileOutputStream(tmpFile)); D9^7m j?e
output.writeInt(nStartPos.length); oeNzHp_
for(int i=0;i<nStartPos.length;i++) #\b ;2>
{ agY5Dg7
// output.writeLong(nPos); Qq0O0U
output.writeLong(fileSplitterFetch.nStartPos); E/"SU*Co
output.writeLong(fileSplitterFetch.nEndPos); 6GOg_P
} $r"A@69^RS
output.close(); wW()Zy0)
} xKW"X
catch(IOException e){e.printStackTrace ();} :Y.e[@!1x
catch(Exception e){e.printStackTrace ();} ~L){O*Z
} 1l]C5P}E
A9n41,h
4Iq5+Q
//读取保存的下载信息（文件指针位置） VG\mo?G
private void read_nPos() " Z;uu)NE
{ " dT>KQ
try{ !Zj#.6c9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); no3Z\@%
int nCount = input.readInt(); cj^bh
nStartPos = new long[nCount]; Qu}N:P9l?X
nEndPos = new long[nCount]; %]GV+!3S
for(int i=0;i<nStartPos.length;i++) Vi,Y@+4
{ Y`]rj-8f0B
nStartPos = input.readLong(); ,eK2I Ao
nEndPos = input.readLong(); q2Rf@nt
} QT_^M1%
input.close(); N(7u],(Om
} poY8 )2
catch(IOException e){e.printStackTrace ();} `$Kes;[X
catch(Exception e){e.printStackTrace ();} _FFv#R*4
} -$ali[
qvN"1=nJ
~y@& }
private void processErrorCode(int nErrorCode) Bt6xV<jD
{ w06gY
System.err.println("Error Code : " + nErrorCode); '8={ sMy
} Fva]*5
S| "TP\o
PHl4 vh#E!
//停止文件下载 R25-/6_V>
public void siteStop() GDmv0V$6
{ W+/2c4$F3
bStop = true; h.D^1
for(int i=0;i<nStartPos.length;i++) 4L$};L
fileSplitterFetch.splitterStop(); i]@c.QiFN
YR8QO-7 .)
wKLN:aRF2
} D{3fhPNU<b
} P|v ?
//负责部分文件的抓取 lR[z<2w\
**FileSplitterFetch.java &&*wmnWCS{
*/ [[$Mh_MD
package NetFox; dL(4mR8
Hq-v@@0 *
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import java.io.*; hvL6zCi
import java.net.*; `{WCrw6)
1V\1]J/
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public class FileSplitterFetch extends Thread { {~"Em'}J
XJ _%!
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String sURL; //File URL '1lx{UzD
long nStartPos; //File Snippet Start Position G-sa L*
long nEndPos; //File Snippet End Position |/t K-c6J
int nThreadID; //Thread's ID JQr36U
boolean bDownOver = false; //Downing is over >["Kd.ye
boolean bStop = false; //Stop identical "|\94
FileAccessI fileAccessI = null; //File Access interface hN}5u"pS
&#%D.@L
[@zkv)D6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lvG3<ls0K$
{ . *Z#cq0
this.sURL = sURL; F-i&M1\_
this.nStartPos = nStart; |:}L<9Sq
this.nEndPos = nEnd; 0x6@{0
nThreadID = id; 8db6(Q~P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *eMLbU7
} /T{mS7EpYc
|})rt5|f1!
ruWye1X;
public void run() bf{Ep=-
{ VgUvD1v?}
while(nStartPos < nEndPos && !bStop) hN!.@L
{ y.%i
cx<h_
vDWr|M%``l
try{ DU(X,hDBF
URL url = new URL(sURL); Scf.4~H 0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &,F elB0*
httpConnection.setRequestProperty("User-Agent","NetFox"); PaA6Z":
String sProperty = "bytes="+nStartPos+"-"; 1ME|G"$;
httpConnection.setRequestProperty("RANGE",sProperty); !(}OBZ[*
Utility.log(sProperty); <'VA=orD
/^NJ)9IB
x={kjym L
InputStream input = httpConnection.getInputStream(); "rL"K
//logResponseHead(httpConnection); Sw/J+FO2
A<]&JbIt
Xk;Uk[
byte[] b = new byte[1024]; wX@H &)<s
int nRead; L/c4"f|.*v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T$f:[ye]Z
{ zv&ePq\#
nStartPos += fileAccessI.write(b,0,nRead); m<~>&mWr
//if(nThreadID == 1) 9$8X>T^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L,tZh0
} ]U#JsMS
6_x}.bkIx=
p^}L
Utility.log("Thread " + nThreadID + " is over!"); ^"PfDTyA
bDownOver = true; :A,O(
//nPos = fileAccessI.write (b,0,nRead); T,A!5V>cX
} 5R&x{jf$
catch(Exception e){e.printStackTrace ();} &%@/Dwr
} wbn^R'
} 7cy+Nz
Fa6H(L3
j'#)~>b
//打印回应的头信息 ^f!Zr
public void logResponseHead(HttpURLConnection con) Xq[:GUnt
{ xq8}6Q
for(int i=1;;i++) X^u4%O['
{ 3}v0{c
String header=con.getHeaderFieldKey(i); nYo&x'
if(header!=null) A&xab
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >|y>e{P
Utility.log(header+" : "+con.getHeaderField(header)); F0X5dv
else "v*oga%
break; yIn/Y0No
} 6tDg3`w>
} 8ct+?-3g
oSpi{ $x
oFX"F0rx
public void splitterStop() m4wPuW
{ Cb4d|yiS8
bStop = true; @'6S[zU
} @&/s~3
3U :YA&K(
cg>!<T*
} k8!hvJ)?
UUt~W
ZJiuj!
/* $`-SVC
**FileAccess.java 1jR=h7^=
*//文件访问(定位，写) S.zg&
package NetFox; ,<R>Hiwg/s
import java.io.*; PmuEL@'^ U
N` @W%
PT 0Qzg
public class FileAccessI implements Serializable{ z(8)1#(n7
h0'8NvalQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dm/-}
RandomAccessFile oSavedFile; LC~CPV'F
long nPos; tuL\7 (R
hg<"Yg=
,I9][_
public FileAccessI() throws IOException ?uNTUU,
{ 4i ~eTb
this("",0); ze#rYNvo/
} 1Xk{(G<\
}.fZy&_
FF~on06!
public FileAccessI(String sName,long nPos) throws IOException D;16}D
{ .b!OZ
oSavedFile = new RandomAccessFile(sName,"rw"); hlSB7D"d
this.nPos = nPos; W>aQ tT
oSavedFile.seek(nPos); %8rr*l5
} I{*.htt{
/r::68_KQP
rw40<SS"Z
public synchronized int write(byte[] b,int nStart,int nLen) i{1)=_$Vt`
{ y{&{=1#
int n = -1; !9ceCnwbNN
try{ mM\!4Yi`7
oSavedFile.write(b,nStart,nLen); df21t^0/
n = nLen; 2yi*eR
} [FeJ8P>z
catch(IOException e) =Ov;'MC
{ x`j$9XN5
e.printStackTrace (); L:k@BCQM
} l"~h1xk~
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>h/)r6
return n; ~8Dd<4?F]
} "R\\\I7u
kcma/d
dZ;~b(CA
} 5sA>O2Rt>
6a2w-}Fs
{$u@6& B
/* ^)%wq@Hi
**SiteInfoBean.java lhIr]'?l
*/ q6m87O9
package NetFox; $J;=Ux)$
q)z1</B-
Xx9~
public class SiteInfoBean { =w;xaxjL
U(Hq4D
}ii]cY
private String sSiteURL; //Site's URL RL]lt0O{
private String sFilePath; //Saved File's Path j.yr5%
private String sFileName; //Saved File's Name [<3Q$*Ew
private int nSplitter; //Count of Splited Downloading File yW6[Fpw
#Ko+_Hm?4
m?kIa!GM=
public SiteInfoBean() tKqCy\-q
{//nSplitter的缺省值为5 "#eNFCo7k
//default value of nSplitter is 5 =-1^K
this("","","",5); H$qdU!c
} i5~ /+~
~1wdAq`'a
~M9n<kmE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PUFW^"LV
{ NId~|&\
sSiteURL= sURL; #*;fQ&p
sFilePath = sPath; (j"~]T!)1
sFileName = sName; qeO6}A"^|
this.nSplitter = nSpiltter; <J_,9&\J
A](}"Pi!n
krnk%ug
} n-| i
0.+Z;j
2O)Kn q
public String getSSiteURL() *mhw5Z=!
{ f!R^;'a
return sSiteURL; }zfLm`vJ
} p~zTRnm
]2sZu7
XGup,7e9
public void setSSiteURL(String value) [{!j9E?(
{ OXCml(>{
sSiteURL = value; $q@RHcj
} 63dtO{:4
e!x-:F#4j
Vi-!E
public String getSFilePath() 2] wf`9ZH
{ Z$=$oJzB
return sFilePath; eRqexqO!
} DBh/V#* D
BHBT=,sI
BMsy}08dQ
public void setSFilePath(String value) ;NVTn<Uj
{ $8ww]}K
sFilePath = value; :x5o3xE
} 3/|{>7]1
snzH}$Ls
D2*Q1n
public String getSFileName() jE5 9h
{ U,3K6AZA 7
return sFileName; *z:lq2"G
} T[9jTO?W2
ScmzbDu
iW%0pLn
public void setSFileName(String value) ;%.k}R%O@
{ GN"LU>9|
sFileName = value; -+2xdLa63
} *E q7r>[
n~cm?"
91Sb=9
public int getNSplitter() M@ZpgAfq
{ vh.tk^&
return nSplitter; *ww(5 t
} k#G7`dJl
>-WOw
3T^dgWXEG
public void setNSplitter(int nCount) t-m,~IoW
{ |y=F (6Z
nSplitter = nCount; z`{zqP:
} weadY,-H8
} mP+yjRw
T:5%sN;#O
`%:(IGxz
/* Mp}NUQHE
**Utility.java m&c(N
*/ 7n]%`Yb
package NetFox; :u+#:8u
I`>%2mP[C
Gl:T
public class Utility { vyy\^nL
"<R 2oo)^
#$T"QL@
public Utility() euC,]n.
{ ;P#*R3
[`dipLkr
dR{ V,H7N
} r}Av"
+>({pHZ<S
//线程睡眠 nOzTHg8
public static void sleep(int nSecond) u6d~d\
{ K<(sqH
try{ m(]IxI
Thread.sleep(nSecond); }-iOYSn
} h(up1(x
catch(Exception e) Xh!Pg)|E
{ {Oszq(A
e.printStackTrace (); )C6 7qY[P
} vH8%a8V
} %W@IB8]Vr
fdHxrH>*
//日志 YNk|UwJi
public static void log(String sMsg) sRnMBW.
{ ;Nij*-U4~
System.err.println(sMsg); ;wB3H
} 9x,+G['Zt
)CQ}LbXZy
rNp#5[e
public static void log(int sMsg) ??Ac=K\
{ yK3z3"1M?
System.err.println(sMsg); F tjm@:X
} P2F>iK#U
} OSk9Eb4ld
B[50{;X
nsk 6a
/* E~^'w.1
**TestMethod.java A4h/oMis
*/ 1fZ:^|\
package NetFox; P#PQ4uK \
L~~Yh{<
l[k$O$jo
public class TestMethod { Q8i6kf!
U)8]pUI+/P
_TF>c:m3
public TestMethod() =ndKG5
{ ///xx/weblogic60b2_win.exe 6Tnzg`0I
try{ t;3.;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R3A^VE;qP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (z7#KJ1+Aw
SiteFileFetch fileFetch = new SiteFileFetch(bean); !)34tu2
fileFetch.start(); ,vPF=wq
} lH.2H
catch(Exception e){e.printStackTrace ();} RSC-+c6 1
M-Bw9`#Jw
CgC wM=!r
} eHR<(8c'f
wQT'~'kL
>^&+,*tsS4
public static void main(String[] args) 2X_ef
{ .&y1gh!=
new TestMethod(); m@YLZ
} 3 6 ;hg#
} 7}k8-:a%
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