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)); UW&K\P
} ~I@ %ysR
for(int i=0;i<nEndPos.length-1;i++) +<)H2
{ gyobq'o-
nEndPos = nStartPos[i+1]; Dk}txw}#
} 5KW n>n
nEndPos[nEndPos.length-1] = nFileLength; c@$W]o"A
} L"}2Y3
} S^r[%l<'n
.]/k#Hv
W,.Exh
//启动子线程 nbBox,zW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y27MG
for(int i=0;i<nStartPos.length;i++) `&J=3x
{ 70Ei<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @1V?94T1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F 7X] h
nStartPos,nEndPos,i); 9Yji34eDZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k"+/DK,:
fileSplitterFetch.start(); ?$=Ml$
} h4c4!S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8< z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \j0016;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nr%P11U\c
nEndPos = " + nFileLength); c22L]Sxo
// fileSplitterFetch[nPos.length-1].start(); FB O_B
wdRk+
pZ 7KWk4
//等待子线程结束 |^O3~!JP(>
//int count = 0; hne}G._b
//是否结束while循环 JR|P]}
boolean breakWhile = false; l>pnY%(A
MaP-
uy([>8uu
while(!bStop) p%5(Qqmlk
{ .19_EQ>+
write_nPos(); rrl{3 ?
Utility.sleep(500); D;Y2yc[v
breakWhile = true; sbV_h;<
g8]$BhRIfr
QLZ%m$Z
for(int i=0;i<nStartPos.length;i++) N._^\FRyn
{ J:\O .F#Fi
if(!fileSplitterFetch.bDownOver) la{o<||Aq
{ lht :%Ts$
breakWhile = false; Gk)6ljL
break; g?>
} Olr'n% }
} KXcE@q9
if(breakWhile) SKVQ !^o
break; Cil1wFBb
$ 3R5p
xS_tB)C
//count++; ;eP.B/N
//if(count>4) nW]T-!
// siteStop(); ?d)FYB
} ]u%Y8kBe
wfM|3GS+.
dEfP272M
System.err.println("文件下载结束！"); 8%;]]{(B
} h[gKyxZ/t
catch(Exception e){e.printStackTrace ();} LP}j0)n
} VB~Do?]*k%
/[|A(,N}{
?aU-Y_pMe
//获得文件长度 =@.5J'!
public long getFileSize() 2~@Cj@P]
{ df9$k0Fx
int nFileLength = -1; =Ct$!uun
try{ 2XV3f$,H
URL url = new URL(siteInfoBean.getSSiteURL()); |L6 +e*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VpB+|%@p
httpConnection.setRequestProperty("User-Agent","NetFox"); *4g:V;L
@Cl1G
k'K 1zUBj
int responseCode=httpConnection.getResponseCode(); }Q_ }c9?
if(responseCode>=400) W<H<~wf#
{ #a!qJeWm0
processErrorCode(responseCode); K}Lu1:~
return -2; //-2 represent access is error (E \lLlN
} S~{}jvc
}M${ _D
l8d }g
String sHeader; dhi9=Co;
G V%@A
y{QF#&lW
for(int i=1;;i++) -aIB_
{ hFDo{yI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <2fvEW/#v
//Utility.log(in.readLine()); i$z*~SuM#
sHeader=httpConnection.getHeaderFieldKey(i); O_&Km[
if(sHeader!=null) II(P
{ S[RVk=A1
if(sHeader.equals("Content-Length")) I>@Qfc bG
{ 9S{0vc/2@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <is%lx(GDX
break; z5t"o !
} - s0QEQ
} zG~nRt{4
else $!:xjb
break; Wq*W+7=.
} FMAt6HfU
} qZX\riR
catch(IOException e){e.printStackTrace ();} +qmV|$rmM
catch(Exception e){e.printStackTrace ();} j.UO>1{7
./}W3
mA6Nmq%{ F
Utility.log(nFileLength); incUa;
.Yxf0y?uv
iIU>:)i
return nFileLength; $%5!CD1)
} DZV U!J
# |,c3$
NV9H"fI
//保存下载信息（文件指针位置） >~\CiV4^
private void write_nPos() 7R>Pk9J
{ <_-8)abK
try{ IHj9n>c)[
output = new DataOutputStream(new FileOutputStream(tmpFile)); _E xd:
output.writeInt(nStartPos.length); 41\V;yib
for(int i=0;i<nStartPos.length;i++) W. p'T}2
{ \rmge4`4
// output.writeLong(nPos); >w|2 ~oK
output.writeLong(fileSplitterFetch.nStartPos); r<-@.$lf
output.writeLong(fileSplitterFetch.nEndPos); #l_hiD`;r
} F6-U{+KU$!
output.close(); be~'}`>
} Bc51 0I$c
catch(IOException e){e.printStackTrace ();} q%k _C0
catch(Exception e){e.printStackTrace ();} M}`G}*
} t`vIcCXqyl
Z+C&?K
&BQ%df<y\
//读取保存的下载信息（文件指针位置） LArfX,x3i
private void read_nPos() TS;?>J-
{ [^A>hs*
try{ p`3$NCJN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fnudu0k
int nCount = input.readInt(); |%5nV=&\
nStartPos = new long[nCount]; %1e{"_$O9
nEndPos = new long[nCount]; hOIk6}r4X
for(int i=0;i<nStartPos.length;i++) )n17}Qm`V
{ "6o5x&H
nStartPos = input.readLong(); C/A~r
nEndPos = input.readLong(); #nJ&`woZt
} "QCViR
input.close(); w}``2djR'W
} S$Fq1
catch(IOException e){e.printStackTrace ();} ^ot9Q
catch(Exception e){e.printStackTrace ();} Zcxj.F(,
} KZ/2#`
1IV R4:a
>O}J*4A>+#
private void processErrorCode(int nErrorCode) B;xGTl@8
{ XLsOn(U\&
System.err.println("Error Code : " + nErrorCode); doV+u(J~
} Z1M{5E
glP W9q,f
pt- 1>Ui
//停止文件下载 f2RIOL,
public void siteStop() o:Q.XWa@MG
{ jd?NN:7
bStop = true; Af7&;8pM
for(int i=0;i<nStartPos.length;i++) HU+zzTgI
fileSplitterFetch.splitterStop(); =CjN=FM
rgXD>yu(
K^+}__;]
} J9yB'yE8
} ?u_O(eg
//负责部分文件的抓取 Rz!!;<ye8
**FileSplitterFetch.java ELQc: t -2
*/ TeWpdUCO
package NetFox; $(eqZ<y
?<-ins
hZNAI
import java.io.*; UqZ#mKi
import java.net.*; 2x dN0S
f/RDo4
"N*i!h
public class FileSplitterFetch extends Thread { ad[oor/7|
h5.AM?*TNd
]~-vU{
String sURL; //File URL "4e{Cq
long nStartPos; //File Snippet Start Position OFcqouGE
long nEndPos; //File Snippet End Position 6$6Qk !%
int nThreadID; //Thread's ID (w{C*iB
boolean bDownOver = false; //Downing is over +2S#3m?1
boolean bStop = false; //Stop identical TkSeDP
FileAccessI fileAccessI = null; //File Access interface (k&r^V/=
JLH,:2
YN 31Lo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A J"/T+g_
{ mY !LGN
this.sURL = sURL; <<.%Gk
this.nStartPos = nStart; 7__?1n~{
this.nEndPos = nEnd; (GI]Uyn
nThreadID = id; Y+'522er
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g?d*cwtU
} zCdzxb_h"
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N_),'2
public void run() *oU-V#
{ Y]>Qu f.!
while(nStartPos < nEndPos && !bStop) <tp#KZE
{ u.Z,HsEOb
N"q C-h
e3b|z.^8
try{ dw]wQ\4B
URL url = new URL(sURL); l9X\\uG&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T&PLvyBL
httpConnection.setRequestProperty("User-Agent","NetFox"); FkJX)
String sProperty = "bytes="+nStartPos+"-"; 1xE*quhrh
httpConnection.setRequestProperty("RANGE",sProperty); =FtJa3mHK
Utility.log(sProperty); K]Onb{QY
aj)?P
e<[0H 8
InputStream input = httpConnection.getInputStream(); OGqsQ
//logResponseHead(httpConnection); OlF5~VAbfb
v9R"dc]0h
F_&bE@k
byte[] b = new byte[1024]; 0[T>UEI?
int nRead; {-?8r>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @"E{gM@B
{ >hbT'Or@
nStartPos += fileAccessI.write(b,0,nRead); {#'M3z=
//if(nThreadID == 1) V9Gk``F<RZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a4L0Itrp
} lSk<euCYs
czv )D\*
=YRN"
Utility.log("Thread " + nThreadID + " is over!"); ^#A[cY2eM
bDownOver = true; *b >hZkObn
//nPos = fileAccessI.write (b,0,nRead); r9d dVD
} t@O4!mFH
catch(Exception e){e.printStackTrace ();} 9M$N>[og
} ko%B`
} $ZOKB9QccC
(66DKG
1KtPq,
//打印回应的头信息 c&JYbq
public void logResponseHead(HttpURLConnection con) U DC>iHt
{ mC}!;`$8p
for(int i=1;;i++) >7^+ag~&
{ r!7e:p JLO
String header=con.getHeaderFieldKey(i); )QvuoaJQ
if(header!=null) G]- wN7G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MlM2(/ok
Utility.log(header+" : "+con.getHeaderField(header)); f;"6I
else 4: <=%d
break; :<$IGzw}.
} X&qa3C})
} a|v}L,
}lzQMT
>`@yh-'r
public void splitterStop() fx783
{ k-LT'>CWl
bStop = true; M"t=0[0DM:
} i!=28|_
^QKL}xiV:
&MlBpI
} <.h\%&'U
!tNJLOYf
Fc"&lk4e
/* *!gj$GK@%
**FileAccess.java QFfKEMN
*//文件访问(定位，写) 6^DsI
package NetFox; f @cs<x
import java.io.*; _>moza
7Z;w<b~
XFg.Z+ #
public class FileAccessI implements Serializable{ `=0J:
CY4_=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;|hEXd?b
RandomAccessFile oSavedFile; B!(t<W8cu
long nPos; PZdYkbj
epH48)2
.2b) rKo~
public FileAccessI() throws IOException ^!*?vHx:
{ Z-{!Z;T)z
this("",0); (&6C,O~n^.
} /I'n]
Y,bw:vX
9o7d3ir)
public FileAccessI(String sName,long nPos) throws IOException #f'(8JjY
{ Y"uFlHN&i
oSavedFile = new RandomAccessFile(sName,"rw"); Jb~-)n2
this.nPos = nPos; E00zf3Jgv'
oSavedFile.seek(nPos); UEq;}4Bo
} Ohm>^N;
>q&Q4E0
(Jw[}&+
public synchronized int write(byte[] b,int nStart,int nLen) !k&~|_$0@
{ Te8BFcJG
int n = -1; id-VoHdK
try{ Hr$oT=x[
oSavedFile.write(b,nStart,nLen); MGO.dRy_
n = nLen; c#G]3vTdE
} s'^zudx
catch(IOException e) ;!@\|E
{ t#y
e.printStackTrace (); xX'Uq_Jv
} ndm19M8Y|
gKZ{O
|<.b:e\4
return n; {/BEO=8q2
} dv0TJ 0%
0;)6ZU
|zu>G9m
} wS2iyrIB
#^Dc:1,
SPV'0* Z
/* j8os6I
**SiteInfoBean.java tji,by#E/%
*/ !dLz ?0
package NetFox; mm=Y(G[_%y
ucj)t7O
%6<Pt
public class SiteInfoBean { O#7ldF(
<LW|m7
$Yz &x%Lb
private String sSiteURL; //Site's URL e>t9\vN#bx
private String sFilePath; //Saved File's Path N,ik&NIWy
private String sFileName; //Saved File's Name FZ>*<&
private int nSplitter; //Count of Splited Downloading File vc2xAAQ
yT&bS\
.Qh8I+Q%
public SiteInfoBean() ^BM/K&7^
{//nSplitter的缺省值为5 %:o@IRTRU
//default value of nSplitter is 5 +^+wS`Y
this("","","",5); Jb-wvNJu
} >V(2Ke Y
<nsl`C~6g0
l1cBY{3QD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LbR/it'}
{ RQ,(?I*8\
sSiteURL= sURL; >`NY[Mn
sFilePath = sPath; !E_uQ?/w]Z
sFileName = sName; z K8#gif@
this.nSplitter = nSpiltter; ~DZ;l/&Mz7
p2~Q
YLd 5
} d L%E0o
i`]M2Q
,:\2Lf
public String getSSiteURL() l3MbCBX2
{ qd|*vE
return sSiteURL; `A <yDy
} UxicqkX
24N,Bo 3
Dlj=$25
public void setSSiteURL(String value) H[N&Wiq/|
{ ^z&xy41#B
sSiteURL = value; iL 4SL}P
} J+*rjdI
$fKwJFr
L)nVNY@Mc
public String getSFilePath() (+]k{
{ GPx S.&
return sFilePath; |>3a9]
} ['km'5uZ^
Rg[e~##
>!)VkDAG
public void setSFilePath(String value) P)ZSxU
{ jZ D\u%
sFilePath = value; ex!^&7Q(
} 4}LF>_+=
@B9|{[P
x>8f#B\Mr
public String getSFileName() T (2,iG8
{ y]jh*KD[
return sFileName; Mz++SPG7
} ^Js9E
3Xh&l[.
[S4\fy0
public void setSFileName(String value) jATU b-
{ H4:TYh
sFileName = value; 6$6NVq
} ESrWRO f9
rFy9K4D
Na~_=3+a
public int getNSplitter() wO!hVm,Ta
{ Y!7P>?)`,X
return nSplitter; k(qQvn
} Wq9s[)F"Z
}"&(sYQ*`
Ro1' L1:
public void setNSplitter(int nCount) ^,KR0
{ *Yr-:s9J9
nSplitter = nCount; xY'g7<})$
} ,xh9,EpBk
} /MU<)[*Ro
H0(zE*c~
Fp]8f&l8
/* -.*\J|S@g
**Utility.java M<p)@p
*/ :9h8q"T
package NetFox; ,?d%&3z<a
]czy8n$+
R]Yhuo9,&n
public class Utility { aXJe"IT.u
y*(YZzF
v4zd x)
public Utility() ww,c)$
{ >ATW/9r
OX`n`+^D
f!J^vDl
} \O:xw-eG
F:@Ixk?E
//线程睡眠 4AM*KI
public static void sleep(int nSecond) $~YuS_sYg
{ c~'kW`sNV
try{ @iRVY|t/
Thread.sleep(nSecond); 1}uDgz^
} z )pV$
catch(Exception e) I7~|!d6
{ l =yHx\
e.printStackTrace (); 9A_7:V]_
} /)I9+s#q9o
} vvM)Rb,
hjG1fgEj
//日志 ,![=_d
public static void log(String sMsg) mCGcM^21-x
{ uf^:3{1
System.err.println(sMsg); 0|ps),
} O$H150,Q
H+;wnI>@
_5T7A><q<
public static void log(int sMsg) ^8m+*t
{ V"p<A
System.err.println(sMsg); Vd0GTpB?1
} qj6`nbZ{va
} t4IJ%#22
0uz"}v)
Rpk`fxAO
/* `"H?nf0
**TestMethod.java Ds87#/Yfv
*/ rxK0<pWJhx
package NetFox; (OqJet2{+
X4$e2f
[j?<9
public class TestMethod { gHx-m2N
x3s^u~C)(w
Wn^^Q5U#
public TestMethod() L)}V[j#
{ ///xx/weblogic60b2_win.exe +*J4q5;E[?
try{ c2^7"`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \Wc/kY3&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >y9o&D
SiteFileFetch fileFetch = new SiteFileFetch(bean); yU|ji?)e
fileFetch.start(); uB1!*S1f
} MI(i%$R-A
catch(Exception e){e.printStackTrace ();} C.E>)
A7C+&I!L
AE&n^vdQW
} GX)QIe~;qJ
g8+,wSE
*$(CiyF!
public static void main(String[] args) @(c<av?
{ @S7=6RKa[
new TestMethod(); H040-Q;S'
} : xZC7"
} aELT"b,x
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