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)); ]rW8y%yD
} i2`0|8mw'
for(int i=0;i<nEndPos.length-1;i++) ;nB2o-%
{ T:!MBWYe|
nEndPos = nStartPos[i+1]; LfX0Z=<
} ]k+m=OR{/
nEndPos[nEndPos.length-1] = nFileLength; r4eUZ .8R
} 9*}gl3y
} X+ f9q0
rsF:4G"%
SRz&Nb
//启动子线程 TzM=LvA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2QayM?k8
for(int i=0;i<nStartPos.length;i++) (0jr;jv
{ #":a6%0Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7g6RiH}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 59!)j>f
nStartPos,nEndPos,i); fLB1)kTS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 77We;a
fileSplitterFetch.start(); .3wY\W8Dr-
} o3h-=t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kx{!b3"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D1X{:#|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]\;xN~l
nEndPos = " + nFileLength); 'G#SLqZy
// fileSplitterFetch[nPos.length-1].start(); A=`*r*
<qY5SV,
F?4Sz#
//等待子线程结束 ;^-:b(E
//int count = 0; xP@/9SM
//是否结束while循环 r nBOj#N
boolean breakWhile = false; >XE`h9
,w`~K:b.
yJD>ny
while(!bStop) aRwnRii
{ f7+Cz>R
write_nPos(); (9GbG"
Utility.sleep(500); ./w{L"E
breakWhile = true; R6@uM<
9<cOYY
jXR16|
for(int i=0;i<nStartPos.length;i++) 5(J^N
{ /V^sJ($V$~
if(!fileSplitterFetch.bDownOver) "ahvNx;x
{ Qpu3(`d<
breakWhile = false; ;CmOsA,1
break; !N~*EI$
} \ 4gXY$`@
} -g~~]K%
if(breakWhile) dDlG!F_=
break; <lo`q<q
GqUSVQ
)%mAZk-*;^
//count++; sh6(z?KP
//if(count>4) =_QkH!vI
// siteStop(); l)8sw=
} 7/>a:02
A&N*F"q
Sdc*rpH"(
System.err.println("文件下载结束！"); Yx1 D)
} `-O=>U5nH
catch(Exception e){e.printStackTrace ();} 2R`u[
} #&siHHs \
zilaP)5x6
&O tAAE
//获得文件长度 og-]tEWA1
public long getFileSize() \"d?=uFe
{ ?}sOG?{
int nFileLength = -1; v*r9j8
try{ grbTcLSF
URL url = new URL(siteInfoBean.getSSiteURL()); B>|5xpZM12
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &;v!oe
httpConnection.setRequestProperty("User-Agent","NetFox"); ;BI)n]L
s*JE)
3qo e^e
int responseCode=httpConnection.getResponseCode(); o}~3JBnT
if(responseCode>=400) yWHne~!
{ sXB+s
processErrorCode(responseCode); V2Y$yV8g1
return -2; //-2 represent access is error >&hX&,hG
} m2b`/JW
w3bIb$12
u^=@DO'
String sHeader; YMu)
8^X]z|[d2
},PBqWe
for(int i=1;;i++) UC|JAZL
{ fn1pa@P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G(\Ckf:
//Utility.log(in.readLine()); s.y}U5Ty?P
sHeader=httpConnection.getHeaderFieldKey(i); g1qi\axm
if(sHeader!=null) FpzP#;
{ `Bu9Nq
if(sHeader.equals("Content-Length")) EcW1;wH
{ *V|zx#RN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wk[)+\WQ?
break; P<L&c_u
} k7Oy5$##
} d_T<5Hin
else e?<D F.Md+
break; :t>Q:mX(N
} }17bV, t
} 4$Pr|gx
catch(IOException e){e.printStackTrace ();} #!d]PH746
catch(Exception e){e.printStackTrace ();} 0yTQ{'Cc
QUp?i
(C\r&N
Utility.log(nFileLength); ifrq
<E}N=J'uJ
)ddsyFGW
return nFileLength; C1 {ZW~"YI
} xid:"y=_&
T} 8CfG_j
<gcmsiB|
//保存下载信息（文件指针位置） o)!m$Q~v
private void write_nPos() owMmCR
{ oD,C<[(p
try{ \`gEu{
output = new DataOutputStream(new FileOutputStream(tmpFile)); iGa}3pF
output.writeInt(nStartPos.length); CB]l[hM$
for(int i=0;i<nStartPos.length;i++) T*\$<-^
{ M=+M8M`Iy
// output.writeLong(nPos); A^g>fv
output.writeLong(fileSplitterFetch.nStartPos); hVZo"XUb
output.writeLong(fileSplitterFetch.nEndPos); ^ LbGH<#J
} ohplj`X[21
output.close(); 6Ahr_{
} 7TdQRB
catch(IOException e){e.printStackTrace ();} 6 [ _fD
catch(Exception e){e.printStackTrace ();} Ilef+V^qr
} GZ"/k<~0
CWvlr nv
TkT-$=i
//读取保存的下载信息（文件指针位置） %~\
private void read_nPos() qUg9$oh{LI
{ v= 8VvT8
try{ Ky6+~>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6eo4#/+%
int nCount = input.readInt(); H:Lt$
nStartPos = new long[nCount]; 1p=&WM
nEndPos = new long[nCount]; >Bx8IO1_\d
for(int i=0;i<nStartPos.length;i++) h--45`cE
{ ucM.Ro=@
nStartPos = input.readLong(); ~oFh>9u
nEndPos = input.readLong(); eP?~-#
} +"Ub/[J{G1
input.close(); +!xu{2!
} V4\560
catch(IOException e){e.printStackTrace ();} xp=Zd\5W$
catch(Exception e){e.printStackTrace ();} -3]|[
} 9m~t j_
w&C1=v -h
#%WCL'6B
private void processErrorCode(int nErrorCode) ?\M)WDO
{ mR,O0O}&
System.err.println("Error Code : " + nErrorCode); ]|y}\7Aa
} k-vA#
B{99gwMe]
.5z&CJDiIi
//停止文件下载 7vq DZg
public void siteStop() Dt|fDw$]D
{ yDuq6`R*
bStop = true; Pl?}>G
for(int i=0;i<nStartPos.length;i++) "5(W[$f*]v
fileSplitterFetch.splitterStop(); 952V@.Zp
wo]ks}9
oX*b<d{\N
} Y2D>tpqNw
} [%?hCc
//负责部分文件的抓取 sL8>GtVo
**FileSplitterFetch.java ;L$,gn5H
*/ d.I%k1`(
package NetFox; vlAy!:CV
UeNF^6sWu0
F;W'
import java.io.*; kw#X]`c3
import java.net.*; AbG&9=Ks
D@*|24y
[tz u;/
public class FileSplitterFetch extends Thread { U\?+s2I)v
,0,Oe=d
i=V-@|Z
String sURL; //File URL zg)|rm
long nStartPos; //File Snippet Start Position Fq4lXlSB
long nEndPos; //File Snippet End Position K?JV]^
int nThreadID; //Thread's ID UT~4Cfb
boolean bDownOver = false; //Downing is over `xGT_0&ck
boolean bStop = false; //Stop identical \eT/%$
FileAccessI fileAccessI = null; //File Access interface 3wo'jOb
I<KCt2:X
ovSH}h!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "G@E6{/
{ Y=|CPE%V
this.sURL = sURL; /wlFD,+8
this.nStartPos = nStart; I[%M!_+
this.nEndPos = nEnd; ILNXaJ'0a
nThreadID = id; 5E0wn'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D>S8$]^Dm
} '?b\F~$8
K9^"NS3
xjE7DCmA
public void run() _V&x`ks
{ k3#wLJ
while(nStartPos < nEndPos && !bStop) ZLuPz#
{ qNy-o\;XN
8,H~4Ce3
lj Y
try{ #'wL\3
URL url = new URL(sURL); $q^O%(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sN=KRqe
httpConnection.setRequestProperty("User-Agent","NetFox"); 5Vm Eyb
String sProperty = "bytes="+nStartPos+"-"; 4NJVW+:2
httpConnection.setRequestProperty("RANGE",sProperty); :Nkz,R?
Utility.log(sProperty); &D^e<j}RQ
8a?IC|~Pz
+~:x}QwGT
InputStream input = httpConnection.getInputStream(); n}f3Vrl
//logResponseHead(httpConnection); j+ I*Xw
=^#0.
N7a[B>+`
byte[] b = new byte[1024]; 51z/
int nRead; |MVV +.X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ig+k[`W
{ 2G H)iUmc
nStartPos += fileAccessI.write(b,0,nRead); 8z?$t-DO
//if(nThreadID == 1) mcCB7<. e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^^7gDgT
} n00z8B1j(l
@f\ X4!e*y
:bI,rEW#_
Utility.log("Thread " + nThreadID + " is over!"); }tu4z+T2
bDownOver = true; $G)&J2zL
//nPos = fileAccessI.write (b,0,nRead); )Gmb?!/^
} 3mybG%39
catch(Exception e){e.printStackTrace ();} am3V9"\
} w{~" ;[@
} 1R*1BStc
QP'qG@j[:
N=.}h\{0
//打印回应的头信息 >}mNi:6xq
public void logResponseHead(HttpURLConnection con) dWMccn;-m
{ 3F;EE:
for(int i=1;;i++) [1e.i
{ $x/J+9Ww
String header=con.getHeaderFieldKey(i); 3Sk5I%
if(header!=null) EkDws`@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9GtLMpy
Utility.log(header+" : "+con.getHeaderField(header)); makaI0M
else U-ERhm>uk
break; pz.Y=V\t
} 6V+V zDo
} =P1RdyP
?U=mcdqd
}F~f&<GX6
public void splitterStop() i[mC3ghM6,
{ !'+\]eA
bStop = true; :{x!g6bK@
} kBQ5]Q"
C+DG+_%V*S
dvC0 <*V
} ex{)mE4Cd
Fka1]|j9
5aa}FdUq
/* K3j_C`Se
**FileAccess.java "4KkKi
*//文件访问(定位，写) X>3iYDe
package NetFox; ?0? x+
import java.io.*; 7ZL,p:f
!Jk(&.
<WO&$&
public class FileAccessI implements Serializable{ ?a*fy}A|
zw}@nqp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cb\jrbj6
RandomAccessFile oSavedFile; F">Nrj-bs
long nPos; 0~Um^q*'3
+oE7~64LL
5w]DncdQ~
public FileAccessI() throws IOException &19lk
{ LZgwIMd
this("",0); SJso'6 g
} K-N]h
A9NOeE
H(
public FileAccessI(String sName,long nPos) throws IOException =1%zI%
{ iK$Vd+Lgc
oSavedFile = new RandomAccessFile(sName,"rw"); f6keWqv<GW
this.nPos = nPos; JsZAP
oSavedFile.seek(nPos); %@M00~-
} AGw1Pl8]K
EGp~Vo-
WZfk}To1#
public synchronized int write(byte[] b,int nStart,int nLen) }|w=7^1z
{ 0sq=5 BnO
int n = -1; )pkhir06t
try{ oG|?F4l*
oSavedFile.write(b,nStart,nLen); ykErt%k<n
n = nLen; E geG,/-`
} 23(B43zy
catch(IOException e) ,-w-su=J_
{ $)kk8Q4+K
e.printStackTrace (); jx^|2
} *+_fP|cv
;t.SiA
L7~+x^kw
return n; !=8L.^5c
} V+4k!
}qgqb
X ,V= od>
} S!`4Bl
@d8&3@{R^
-D.BJ(
/* gb!@OZ c
**SiteInfoBean.java f;@b a[
*/ u|_ITwk
package NetFox; SX1Fyy6 w
T! &[
rahHJp.Ws
public class SiteInfoBean { .{'Uvn
<>&e/
J4Q)`Y\~
private String sSiteURL; //Site's URL Thht_3_C,f
private String sFilePath; //Saved File's Path v*C+U$_3\1
private String sFileName; //Saved File's Name lx A<iQia
private int nSplitter; //Count of Splited Downloading File S0Rf>Eo4
7?n*t
(hRgYwUa<
public SiteInfoBean() 89:?.'
{//nSplitter的缺省值为5 #cSw"A
//default value of nSplitter is 5 <3],C)Zwc
this("","","",5); =F^->e0N
} }iiG$?|.
ne!j%9Ar
[9YlLL@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E :'
{ dy8In%
sSiteURL= sURL; L.I}-n
sFilePath = sPath; 34++Rr [G
sFileName = sName; Mc#O+'](f
this.nSplitter = nSpiltter; B $ y44
R:pBbA7E
qH{8n`
} "tg\yem
Nj3^"}V
s)o,Fi
public String getSSiteURL() k#IS,NKE
{ R%]9y]HQ
return sSiteURL; 7YQK@lS
} T}b( M*E
?@g;[310`
PJSDY1T
public void setSSiteURL(String value) QYf/tQg$
{ &4[#_(pk
sSiteURL = value; $Z(g=nS>
} )\I? EU8
Up!ZCZ$RC
<x>k3bD
public String getSFilePath() |)!k@?_
{ dc\u$'F@S
return sFilePath; Yt O@n@1
} u75)>^:I
{'=Nb 5F
pdcwq~4~%
public void setSFilePath(String value) \KnD"0KW
{ %Zv(gI`A
sFilePath = value; I 1VEm?CQ
} ?-.Ep0/
K,L>
l6}b{e
public String getSFileName() o?Tp=Ge
{ e8P!/x-y
return sFileName; _/z)&0DO
} _]?Dt%MkD
@dT: 1s
uz#eO|z@o
public void setSFileName(String value) ;*37ta
{ q_T?G e
sFileName = value; u_[4n
} tmY-m,U
.1[2 CjQ
QE{;M
public int getNSplitter() dPyBY]`
{ z7.C\l
return nSplitter; faL^=CAe
} gQk#l\w_
Z,8+@
Y+"hu2aPkY
public void setNSplitter(int nCount) [ilv/V<
{ d6d(?"
nSplitter = nCount; 4-}A'fTU8
} xJH9qc ME
} -Y jv&5
0@mX4.!
8)q]^
/* yZ(Nv $[5
**Utility.java yK>0[6l
*/ i6g[E4nk
package NetFox; 3Ld ;zW
+{Vwz
sKB-7
public class Utility { :9rhv{6Wp
ubN"(F:!-S
SU#P.y18%
public Utility() < jocfTBk
{ Zm8 u:
+'&_V011<
$vbAcWj
} G}?P r4Gj
@#ho(_U8
//线程睡眠 EBL,E:_)
public static void sleep(int nSecond) Z564K7IV
{ Zxxy1Fl#.[
try{ J:-TINeB
Thread.sleep(nSecond); J%O4IcE
} tx1m36a"
catch(Exception e) (.XDf3
{ ]x(2}h^S
e.printStackTrace (); !K^Z5A_;
} s*~jvL
} :Z]+Z_9p
LOb'<R\p
//日志 U37?P7i's
public static void log(String sMsg) hC 4X Y
{ }$k`[ivBx(
System.err.println(sMsg); eze(>0\f
} fe9& V2Uu
luz%FY:
[|;Zxb:
public static void log(int sMsg) f$S QhK5`
{ +8vzkfr3It
System.err.println(sMsg); 7Ae,|k
} g$-D?~(Z
} Z"%O&O
+D-+}&oW
$8T|r+<
/* >LaL!PnZ
**TestMethod.java 1q233QSW)
*/ =&*QT&e
package NetFox; qL;T&h
QB|fFj58u
.lF\bA|
public class TestMethod { =wR]X*Pan
'hi\98y
U#]eN[
public TestMethod() r5qx! >
{ ///xx/weblogic60b2_win.exe IOSoc 7+"
try{ 7D~O/#dcc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'St= izhd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =&b$W/l)0
SiteFileFetch fileFetch = new SiteFileFetch(bean); -S3+ h$Y8
fileFetch.start(); 5NvyK[w]
} ${?exnb$
catch(Exception e){e.printStackTrace ();} Dx# @D#
&'ETx"
[oN> :
} I7z]%Z
W*DIW;8p
ZM^;%(
public static void main(String[] args) Q|H cg|
{ /,@v"mE7c!
new TestMethod(); tfKeo|DM"
} a*8.^SdzR
} Qu>zO!x
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