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)); C-g,uARX(r
} Z<QNzJ D
for(int i=0;i<nEndPos.length-1;i++) pH(X;OC9S
{ .hUlI3z9
nEndPos = nStartPos[i+1]; ,3!TyQ\m'
} %:j`%F;R
nEndPos[nEndPos.length-1] = nFileLength; ""Oir!4
} 9W,%[
} JeF$ W!!{
h!Y##_&&4
3i\Np =
//启动子线程 9|Ylv:sR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S9^SW3
for(int i=0;i<nStartPos.length;i++) 3Pp+>{2_?
{ h50]%tp\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %V#MUi1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Pz\ByD
nStartPos,nEndPos,i); 4iZg2"[D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CugZ!>;^
fileSplitterFetch.start(); )&Z`SaoP|J
} I8c:U2D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `\'V]9wS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PjXiYc&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OUFy=5(%:
nEndPos = " + nFileLength); G6lC[eK
// fileSplitterFetch[nPos.length-1].start(); F_I!qcEQ
\<dg
?uU_N$x
//等待子线程结束 $zF%F.rln
//int count = 0; l]j;0i
//是否结束while循环 ]{|lGtK %
boolean breakWhile = false; Q [C26U
#,97 ]
|'I>Ojm
while(!bStop) hwA&SS
{ KP 6vb@(6
write_nPos(); |Y?<58[!)
Utility.sleep(500); 5<Uh2c
breakWhile = true; W*Ow%$%2
i`W~-J
QcJC:sP\>
for(int i=0;i<nStartPos.length;i++) mU"Am0Bdjq
{ Y[_|sIy*
if(!fileSplitterFetch.bDownOver) W*DKpJy
{ _1mpsY<k
breakWhile = false; X|G[Ma?
break; E" >`
} oE6`]^^
} [9V}>kS)
if(breakWhile) B#+n$5#FK
break; `)4v Q+A>
wmIe x
Dr[;\/|#
//count++; oI'& &Bt
//if(count>4) ^2{6W6=
// siteStop(); q2'}S A/
} E'98JZ5ga
@vXXf/
o`!#io
System.err.println("文件下载结束！"); ZI1*Cb
} <QC7HR
catch(Exception e){e.printStackTrace ();} l9OpaOVfJ
} #I*{_|}=
}0Uh<v@
W7gY$\1<&
//获得文件长度 /xcXd+k]
public long getFileSize() [\Nmm4
{ mBb3Ta
int nFileLength = -1; H9i7y,[*
try{ !]Qk?T~9-
URL url = new URL(siteInfoBean.getSSiteURL()); YllZ5<}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MkjB4:"
httpConnection.setRequestProperty("User-Agent","NetFox"); D_[NzCv<-
<SQR";
"\T-r2
int responseCode=httpConnection.getResponseCode(); V6'u\Ch|
if(responseCode>=400) h::(b,|f7
{ |)" y
processErrorCode(responseCode); ^suQ7#g
return -2; //-2 represent access is error +P Dk>PdEt
} RAk"C!&^m
i+_=7(e
"Da-e\yA
String sHeader; VzIZT{
HY1K(T
8x LXXB
for(int i=1;;i++) x}Lj|U$r<X
{ pZlt4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]z8/S!?
//Utility.log(in.readLine()); ;|Hpg_~%>
sHeader=httpConnection.getHeaderFieldKey(i); 6R^32VeK($
if(sHeader!=null) C.":2F;-e
{ jDTG15_=
if(sHeader.equals("Content-Length")) 2+DK:T[
{ <|.]$QSi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); EJMd[hMhe
break; K*2s-,b *
} Eb@**%
} Otx>S' 5
else <[-{:dH,5
break; 3e47UquZ
} at{p4Sl
} {.p;V
catch(IOException e){e.printStackTrace ();} ?U[6X|1
catch(Exception e){e.printStackTrace ();} %&VI-7+K
ujkWVE'
_b>{:H&\
Utility.log(nFileLength); g6aqsa
@ S[As~9X
S[yrGX8lu
return nFileLength; VpAwvMw
} @mv G=:k
kksffzG
Ejr'Yzl3_
//保存下载信息（文件指针位置） /kK!xe
private void write_nPos() BqHqS
{ {r$Ewc$Yb7
try{ 1aV32oK
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ok@`<6v
output.writeInt(nStartPos.length); E>i<2
for(int i=0;i<nStartPos.length;i++) FG{,l=Z0
{ CLe{9-o
// output.writeLong(nPos); s8 MQ:eAP
output.writeLong(fileSplitterFetch.nStartPos); 4X7J~
output.writeLong(fileSplitterFetch.nEndPos); a#i|)[
} hGw}o,g
output.close(); .9=4Af
} `q*p-Ju'
catch(IOException e){e.printStackTrace ();} ~x/ka43
catch(Exception e){e.printStackTrace ();} @#hvQ6u
} =M4:nt
+Ek1~i.
RSbq<f>BFo
//读取保存的下载信息（文件指针位置） |<,0*2
private void read_nPos() ti6X=@ P:
{ koS?UYF`
try{ QdcuV\B}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &4}=@'G@
int nCount = input.readInt(); 8!!h6dQgI
nStartPos = new long[nCount]; ^'M^0'_"v
nEndPos = new long[nCount]; ,dK)I1"C
for(int i=0;i<nStartPos.length;i++) @RszPH1B
{ H25Qx;(dTk
nStartPos = input.readLong(); CueC![pj
nEndPos = input.readLong(); Sy1O;RTn`
} |[mmEYc
input.close(); <%%)C>l
} d0ht*b
catch(IOException e){e.printStackTrace ();} !X$19"
catch(Exception e){e.printStackTrace ();} %HtgZeY
} Z|N$qm}
R"JXWw
Gos#=H
private void processErrorCode(int nErrorCode) m%[/w wL
{ AkW>*x
System.err.println("Error Code : " + nErrorCode); x3`JC&hF,q
} WjK[% ;Z!
ok:L]8UN3
z,E`+a;
//停止文件下载 ",vK~m2W_
public void siteStop() z80FMulO
{ .zt&HI.F
bStop = true; vk X+{n
for(int i=0;i<nStartPos.length;i++) ^xNzppz`]C
fileSplitterFetch.splitterStop(); 3h=kn@I
yhbU;qEG9
Jq(;BJ90R
} 5Rs#{9YE
} PH:5
//负责部分文件的抓取 #X%!7tU6
**FileSplitterFetch.java NyRa.hgZ;
*/ t$Ff$(
package NetFox; qwJp&6
UjoA$A!Od;
3<M yb
import java.io.*; (7b9irL&cn
import java.net.*; G'}N?8s1
dL'oKh,
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public class FileSplitterFetch extends Thread { d_pIB@J
X"q[rsB
/ILd|j(e
String sURL; //File URL 'NCqI
long nStartPos; //File Snippet Start Position l5VRdZ4Uf
long nEndPos; //File Snippet End Position & C)1(
int nThreadID; //Thread's ID =. \hCgq
boolean bDownOver = false; //Downing is over %dW;P[0
boolean bStop = false; //Stop identical umq6X8K
FileAccessI fileAccessI = null; //File Access interface T*0;3&sA
f -F}~S
b/R7Mk1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {'wvb "b
{ Z:N;>.3i
this.sURL = sURL; aZ_3@I{d`
this.nStartPos = nStart; f sh9-iY8e
this.nEndPos = nEnd; lkJxb~S
nThreadID = id; C"**>OGe
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +jwk4BU
} N*&T)a
\ HUDZ2 s
wf]?:'}
public void run() ]4[%Sv6]G
{ #;^UW
while(nStartPos < nEndPos && !bStop) _z BfNz9D
{ hI*v)c
h0k?(O
Cx/J_Ro#
try{ FI?J8a
URL url = new URL(sURL); c;X,-Q9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (2>q
httpConnection.setRequestProperty("User-Agent","NetFox"); < B]qqqP
String sProperty = "bytes="+nStartPos+"-"; &QfEDDJ
httpConnection.setRequestProperty("RANGE",sProperty); ,'`yh|}G\
Utility.log(sProperty); &uO-h
612,J
9m2FH~
InputStream input = httpConnection.getInputStream(); cf"&22TQ+Z
//logResponseHead(httpConnection); E%D.a=UX,
|k*bWuXgLs
0ElEaH1z
byte[] b = new byte[1024]; -`\^_nVC
int nRead; G93V=Bk=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YQHpW>z
{ a5ZXrWv
nStartPos += fileAccessI.write(b,0,nRead); ?uL-qsU
//if(nThreadID == 1) x X3I`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q[NoFZ V!
} Ym\<@[3+!
!\1)?&y9j
jR[c3EA ;
Utility.log("Thread " + nThreadID + " is over!"); e_|<tYx><
bDownOver = true; D>W&#A8&y
//nPos = fileAccessI.write (b,0,nRead); XPMUhozV
} \C>IVz<O
catch(Exception e){e.printStackTrace ();} ;K8}Yq9p9
} rm3/R<
} JHm Pa
!<~.>5UQ
+ <E zv
//打印回应的头信息 :ZB.I(v
public void logResponseHead(HttpURLConnection con) `{>/'o
{ `|AH3v1
for(int i=1;;i++) 3]JJCaf
{ ."BXA8c;A
String header=con.getHeaderFieldKey(i); juF=ZW%i
if(header!=null) 5&EBUl}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d-Z2-89K
Utility.log(header+" : "+con.getHeaderField(header)); +VW8{=$
else ,T zlW\?\
break; I|&DXF
} `!I/6d?A
} )=K8mt0qob
YV|_y:-
~%h )G#N
public void splitterStop() |?^qsnB
{ Ieq_XF]U
bStop = true; :^{KY(3
} z{1A x
UTu~"uCR
OwNM`xSa|\
} ySiZ@i4
Y(1?uVYW\d
Z>y6[o
/* C)yw b6
**FileAccess.java ZLKbF9lo
*//文件访问(定位，写) __tA(uA
package NetFox; 0Mn|Yb4p
import java.io.*; r7_%t_O|IL
6g#yzex
hV,T889'
public class FileAccessI implements Serializable{ 'JdK0w#
rWNe&gFM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "y7\F9
RandomAccessFile oSavedFile; %`5K8eB
long nPos; R|)l^~x
ZoJqJWsd
!})Y9oZc8
public FileAccessI() throws IOException -:=m-3*Tg
{ )_j(NX-C:
this("",0); Wm"#"l4
} fCY??su*
"dt}k$Gr
nPI$<yW7F
public FileAccessI(String sName,long nPos) throws IOException N3#^Ifn[
{ L58H)V3Pn
oSavedFile = new RandomAccessFile(sName,"rw"); 5p~5-_JX
this.nPos = nPos; p JF 9Z
oSavedFile.seek(nPos); eA]8M^
} xqg4b{
xWY\,'+Q
kGnT4R*E
public synchronized int write(byte[] b,int nStart,int nLen) 1CZO+MB&"$
{ d42Y`Wu
int n = -1; zq$L[X
try{ +\ "NPK@3
oSavedFile.write(b,nStart,nLen); .7Yox1,
n = nLen; 5({_2meJ:
} @IbZci)1
catch(IOException e) H6nH
{ Y$,~"$su|
e.printStackTrace (); v36Z*I6)5
} ^4]=D nd%
V+lS\E.
Z5U\>7@&8
return n; o58c!44
} "S'Yn-
(m Yi
K5`*Y@
} g.62XZF@
qk^/&j
fsEQ4xN'
/* E6xdPjoWy
**SiteInfoBean.java p]y.N)a
*/ SfY 5Xgp
package NetFox; G,<d;:
T3=h7a %=
[x, `)Fk
public class SiteInfoBean { H2[0@|<<
fH9"sBiO
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private String sSiteURL; //Site's URL xuqG)HthRS
private String sFilePath; //Saved File's Path 4/*@cW
private String sFileName; //Saved File's Name +C7W2!I[G2
private int nSplitter; //Count of Splited Downloading File l+y;>21sTu
sb_/FE5e
) 5Ij
public SiteInfoBean() $E;Tj|W
{//nSplitter的缺省值为5 ydY(*]
//default value of nSplitter is 5 rrgOp5aV"
this("","","",5); fXnewPr=#
} ps`j>vX*
:,qvqh][
/L(}VJg-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4|cRYZj5
{ g#6R(
sSiteURL= sURL; *6u2c%^
sFilePath = sPath; znWB.H
sFileName = sName; TT3GGHR
this.nSplitter = nSpiltter; PvW4%A@0
+CSv@ />3
)+,h}XqlX
} B9 ?58v&
O.y ?q
NB^Al/V@
public String getSSiteURL() \pI {b9
{ nW\W<[O9
return sSiteURL; "|&3z/AUh
} Hiwij,1
oz]3 Tx
}|8^+V&
public void setSSiteURL(String value) 6~{'\Z
{ "G*$#
sSiteURL = value; S"^'ksL\
} )J+OyR=
}#&[[}@th
9qGba=}Ey
public String getSFilePath() #k &#d9}
{ :nl,Ac
return sFilePath; sEfT#$ a^8
} 6pC1C.
Vz-q7*o$S
csJ)Pt?d
public void setSFilePath(String value) ~W4SFp
{ c,)]!{c
sFilePath = value; 2$t%2>1>@
} Gi@c`lRd1
Jwj=a1I 53
|Go$z3bx
public String getSFileName() aTH$+f1?Q
{ [%6)
return sFileName; pH3\X cn
} w03Ur4>T
x)$0Nr62D
t3^`:T\
public void setSFileName(String value) M5:*aCN6P
{ jVoD9H F/
sFileName = value; iY,oaC~?"N
} qZV|}M>P)
j}tGcFwvSN
^ )!eiM
public int getNSplitter() '+iLW~
{ 14uv[z6
return nSplitter; f2Xn!]o
} ~@@$-,}X
Xnh&Kyz`v
^PJN$BJx
public void setNSplitter(int nCount) <|G!Qn?2-
{ 7cB{Iq0+
nSplitter = nCount; EvY^]M_U
} 0SIUp/.
} {<}Hut:a
\WdSj
c`S+>:
/* v,~fG>Y}
**Utility.java +`mI\+y,
*/ 2Ir*}s2{
package NetFox; e$Yvy>I'tS
G^VOA4
bF,.6iKI
public class Utility { F9las#\J
-U9C{q?h
ku}`PS0UGd
public Utility() o>yXEg
{ MwQt/Qv=
d, ?GW
# SJJ@SM
} _"t>72 `
cCx{ ")
//线程睡眠 ,-(D(J;}1
public static void sleep(int nSecond) Ayn$,
{ NZ!I >
try{ {=gJGP/}_
Thread.sleep(nSecond); ./'d^9{
} eMV8`&c'
catch(Exception e) L5|g\Y`
{ AkO);4A;Jd
e.printStackTrace (); 6<5:m:KE
} ln,9v
} X+,0;% p
v&]yzl
//日志 ~>0H k}Hv
public static void log(String sMsg) i tk/1
{ tW-[.Y -M,
System.err.println(sMsg); w"QZ7EyJ
} 4qsxlN>4O
0u( 0*Xl
*0V'rH)
public static void log(int sMsg) Y2dml!QM
{ <|82)hO
System.err.println(sMsg); ,jw`9a
} *O[/- p&7
} Zvfy%k
O%F*i2I:+k
ouFKqRs;
/* <1*\ ~CX
**TestMethod.java R4k+.hR
*/ [)0^*A2
package NetFox; 2@ZRz%(Oa&
KPjAk
/PR4ILed
public class TestMethod { oj'YDQ^uj
O?A%
^si[L52BZ
public TestMethod() ^~bdAO81
{ ///xx/weblogic60b2_win.exe A+4Kj~`!
try{ "f~OC<GdYs
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s6_i>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b9-3
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y}Y~?kE>M|
fileFetch.start(); lHTr7uF(
} zh\"sxL
catch(Exception e){e.printStackTrace ();} 9v3n4=gc
7kT X
tuuwoiQ*`
} Gui[/iY,F
`f~$h?}3-@
Lz:FR*
public static void main(String[] args) %4YSuZg
{ Vw`Q:qo0:b
new TestMethod(); -XwS?*O
} %,ScGQE
} u3wd~.
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