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)); vE^tdzAG
} @Q,Q"c2
for(int i=0;i<nEndPos.length-1;i++) Z@dVK`nD
{ Z" ;q w
nEndPos = nStartPos[i+1]; mrRid}2
} 8Yk*$RR9
nEndPos[nEndPos.length-1] = nFileLength; 17?YN<
} :0B 7lDw
} =q]!"yU[d
ws9IO ?|&G
jr0j0$BF
//启动子线程 3%5YUG@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4j=K3m
for(int i=0;i<nStartPos.length;i++) P#!N
{ -_Z4)"k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N8pL2y:R[P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p&RC#wYu
nStartPos,nEndPos,i); 9o5D3 d K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >nSt<e
fileSplitterFetch.start(); qJ`:$U
} {*B0lr`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MAkr9AKb,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \AroSy9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3E*m.jX
nEndPos = " + nFileLength); Gu~*ZKyJ
// fileSplitterFetch[nPos.length-1].start(); t}_ #N'`
tjFX(;^[
rWL;pM<
//等待子线程结束 <$e|'}>A
//int count = 0; an"~n`g
//是否结束while循环 T8A(W
boolean breakWhile = false; wxvi)|)
9r]|P}yuS
=XR6rR8
while(!bStop) =${.*,o
{ '+_>PBOc
write_nPos(); A_9^S!
Utility.sleep(500); DBHy%i
breakWhile = true; !-7n69:G
U)bv,{-q
0i_:J
for(int i=0;i<nStartPos.length;i++) b`-|7<s
{ *z VN6wG{
if(!fileSplitterFetch.bDownOver) * HKu%g
{ wv3,% lN
breakWhile = false; 'M>m$cCMZ
break; VGQ~~U7}@
} ;Z{D@g+
} QnVr)4"
if(breakWhile) \_1a#|97e
break; )6)bI.BY
v,ssv{gU
VQla.Y
//count++; 2; ^ME\
//if(count>4) JaY"Wfc
// siteStop(); v~Q'm1!O4\
} hU#e\L 7
)cJ>&g4]
} jj)
System.err.println("文件下载结束！"); YGyv)\
} \2s`mCY
catch(Exception e){e.printStackTrace ();} ?A3L8^tR
} tON>wmN
XH!#_jy
/g<Oh{o8
//获得文件长度 ~(d {j}M>
public long getFileSize() SQ>i:D;
{ 5YD~l(,S1]
int nFileLength = -1; sP(+Z^/
try{ Z[. M>|
URL url = new URL(siteInfoBean.getSSiteURL()); 6$r\p2pi0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p)IL(_X)
httpConnection.setRequestProperty("User-Agent","NetFox"); f4f2xe7\Q
Ym6d'd<9(
.hat!Tt9
int responseCode=httpConnection.getResponseCode(); /d3Jd.l!
if(responseCode>=400) q\6(_U#Tl
{ ~skp}g]
processErrorCode(responseCode); !K>iSF<
return -2; //-2 represent access is error Uq .6h
} sasurR|;
5BhR4+1J
{6'Xz
String sHeader; )dT@0Ys%
nYyhQX~]B
%T/@/,7h
for(int i=1;;i++) ~Bzzu %S
{ 9|+6@6VY!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ote,`h
//Utility.log(in.readLine()); eTuqK23
sHeader=httpConnection.getHeaderFieldKey(i); i5 rkP`)j
if(sHeader!=null) R+M&\5
{ n<ZPWlJ
if(sHeader.equals("Content-Length")) y}odTeq
{ 9@ tp#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4_R|3L
break; Kw -SOFE
} -R`{]7V
} 3P cVE\GN
else g$nS6w|5H
break; ~r--dU
} YlHP:ZW-cu
} I~GF%$-G
catch(IOException e){e.printStackTrace ();} " 9Gn/-V>
catch(Exception e){e.printStackTrace ();} V'vR(Wx
"`vRHeCKN
@]=40Yj~w
Utility.log(nFileLength); (eN7s_
Y2H-D{a27
wcGK*sWG-
return nFileLength; qkb'@f=
} }47h0 i
(`tRJWbdz
&k}f"TX2
//保存下载信息（文件指针位置） I.<c{4K5
private void write_nPos() 4DA34m(
{ sXIYl% d
try{ xnP!P2
output = new DataOutputStream(new FileOutputStream(tmpFile)); J+6zV m
output.writeInt(nStartPos.length); )Z}AhX
for(int i=0;i<nStartPos.length;i++) F!omkN
{ =*mT{q@
// output.writeLong(nPos); }Z!D?(
output.writeLong(fileSplitterFetch.nStartPos); 22\!Z2@T/
output.writeLong(fileSplitterFetch.nEndPos); 2QfN.<[-
} x$Dq0FX!%_
output.close(); kx"10Vw
} K@D\5s|1|
catch(IOException e){e.printStackTrace ();} $<}c[Nm
catch(Exception e){e.printStackTrace ();} +#W94s~0V
} +{J8,^z#
ud1M-lY\U
P15 H[<:Fz
//读取保存的下载信息（文件指针位置） UtZ,q!sg
private void read_nPos() cnv>&6a)
{ \/A.j|by,>
try{ \o9 \ikR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }U_ '7_JT
int nCount = input.readInt(); L4#pMc
nStartPos = new long[nCount]; ZCiCZ)oc
nEndPos = new long[nCount]; !rvEo =^
for(int i=0;i<nStartPos.length;i++) wX$:NOO
{ TJ|Jv8j<s
nStartPos = input.readLong(); #(8|9
nEndPos = input.readLong(); .g*j]!_]
} [K!9xM6
input.close(); :6^7l/p
} 8[^'PIz
catch(IOException e){e.printStackTrace ();} PNU(;&2<
catch(Exception e){e.printStackTrace ();} y8Va>ul"U
} P]E-Wp'p
8)i""OD@I
Y+gY"
private void processErrorCode(int nErrorCode) !3ggQG!e
{ 4w4B\Na>l
System.err.println("Error Code : " + nErrorCode); gEASYIQ
} SC{m@
C@rGa7
tYS4"Nfb+
//停止文件下载 DSGcxM+
public void siteStop() s='+[*&&
{ :|7#D,2
bStop = true; " \$^j#o
for(int i=0;i<nStartPos.length;i++) 3r\8v`^>
fileSplitterFetch.splitterStop(); vdQoJWuB
*6uccx7{
i;[y!U
} YFKE>+
} '6KvB
//负责部分文件的抓取 *Ak.KBg
**FileSplitterFetch.java }\pI`;*O|
*/ ~MpikBf
package NetFox; 4#U}bN
D}-.<
#cbgp;,M{I
import java.io.*; 4 1_gak;
import java.net.*; 6CJMQi,kn
rS8a/d~;0
DE?v'7cmA
public class FileSplitterFetch extends Thread { 4<s.|W`
n|`3d~9$&
\-<BUG]=
String sURL; //File URL GK?ual1
long nStartPos; //File Snippet Start Position U"oNJ8&%|
long nEndPos; //File Snippet End Position [oWkd_dK
int nThreadID; //Thread's ID "LyD
boolean bDownOver = false; //Downing is over MvVpp;bd
boolean bStop = false; //Stop identical ;C]Ufk
FileAccessI fileAccessI = null; //File Access interface Vej$|nF
#-hO\ QdC
_z5/&tm_H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LQ0/oYmNc
{ `:/'")+@v
this.sURL = sURL; ^l &lwSRVt
this.nStartPos = nStart; Sb.8d]DW
this.nEndPos = nEnd; UA[`{rf
nThreadID = id; sFU< PgV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $KHm5*;nd
} I[z:;4W}L^
!iXRt")
Z\0Rw>#
public void run() -@TY8#O#-
{ g40Hj Y
while(nStartPos < nEndPos && !bStop) Vns3859$8
{ TS<d?:
bMH~vR
Aq i:h]x
try{ 7Q 3!=b
URL url = new URL(sURL); b0P3S!E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %&ejO=r
httpConnection.setRequestProperty("User-Agent","NetFox"); )m%uSSx#
String sProperty = "bytes="+nStartPos+"-"; Daf|.5>(@
httpConnection.setRequestProperty("RANGE",sProperty); Z~'t'.=z
Utility.log(sProperty); ZR.k'
pP<8zTLn
g` rr3jP
InputStream input = httpConnection.getInputStream(); $ {yct
//logResponseHead(httpConnection); w$2q00R>
1#vy# '
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byte[] b = new byte[1024]; nep#L>LP$x
int nRead; F%>$WN#2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6F\ 6,E
{ XcR=4q|7
nStartPos += fileAccessI.write(b,0,nRead); [-~pDkf:
//if(nThreadID == 1) IUMv{2C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k %I83,+
} Y2|i>5/|<
hA=uoe\
RQ+,7Ir
Utility.log("Thread " + nThreadID + " is over!"); EOPx4+o
bDownOver = true; U)}]Z@I-
//nPos = fileAccessI.write (b,0,nRead); LF|0lAr
} '|}A/`
catch(Exception e){e.printStackTrace ();} 7Sdo*z
} 6v%yU3l
} *&U~Io"U
-jH|L{Iyq}
+VwQ=[y]
//打印回应的头信息 -cqE^qAdX
public void logResponseHead(HttpURLConnection con) fQ+whGB
{ x}G:n[B7_V
for(int i=1;;i++) ?kjQ_K
{ !gh8 Qs
String header=con.getHeaderFieldKey(i); >%/x~UFc5
if(header!=null) =m.Nm-g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ZL|aB886
Utility.log(header+" : "+con.getHeaderField(header)); *-VRkS-G
else 5es t
break; v,4{:y]p
} 0U42QEG2
} {Jn0G;
}'[>~&/"
4uF.kz-cg
public void splitterStop() _^ hg7&dF
{ }[+uHR6L
bStop = true; hSehJjEoM
} <Iw{fj|
,dC.|P' `
'-wmY?ZFxy
} (j}7|*.
y3~=8!Tj?Q
{FIzoR"
/* sn"((BsO<
**FileAccess.java i>M%)HN
*//文件访问(定位，写) *g5bdQ:Av~
package NetFox; "i&)+dr-
import java.io.*; MA .;=T
U>tR:)
zx@!8Z
public class FileAccessI implements Serializable{ G ;j1zs
aH}/+Hu-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a4:GGzt
RandomAccessFile oSavedFile; o30C\
long nPos; "FHJ_$!
CR4O#f8\
v[L+PD U
public FileAccessI() throws IOException M CC4'
{ [>ghs_?dZ
this("",0); #]h X."b2
} 1$Hou
FjCGD4x1N
~5 6&!4
public FileAccessI(String sName,long nPos) throws IOException 2"&GH1
{ Pe`mZCd^
oSavedFile = new RandomAccessFile(sName,"rw"); 8LV6E5Q
this.nPos = nPos; @i ~A7L0/
oSavedFile.seek(nPos); y._'o7%
} ?:r?K|Ku
Y0(4]X \ey
k^ <]:B
public synchronized int write(byte[] b,int nStart,int nLen) eT b!xb
{ X}(s(6
int n = -1; /8;m.J>bf
try{ h$5[04.Q
oSavedFile.write(b,nStart,nLen); |z)s9B;:#i
n = nLen; )rEl{a
} {aAd (~YZ
catch(IOException e) izP)t
{ kZe<<iv
e.printStackTrace (); W&5/1``u\
} dWz?`B{'
;6/WjUDw<|
\2@J^O1,
return n; oC`F1!SfOO
} $0$sM/%
A8f.h5~9
tV!?Ol
} xn*$Ty+
<,CrE5Pl
JQ?`l)4
/* 'K4FS(q
**SiteInfoBean.java <WP@q&^k\
*/ m-t:'B
package NetFox; qfsPX6]
q-!H7o
4r(0+SO
public class SiteInfoBean { +W4}&S
(;#c[eKy
H,}&=SCk
private String sSiteURL; //Site's URL ^+x?@$rq
private String sFilePath; //Saved File's Path >!Yuef <P
private String sFileName; //Saved File's Name %o8o~B|{.U
private int nSplitter; //Count of Splited Downloading File +gd5&
8m") )i-
z>W:+W"o
public SiteInfoBean() $z=%e#(!I
{//nSplitter的缺省值为5 G(t:s5:
//default value of nSplitter is 5 l@);U%\pS
this("","","",5); ?4':~;~
} ,4'gj0
!AwMD
6U{A6hH]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )9H5'Wh#
{ AYnPxiW|
sSiteURL= sURL; r,;ca6>5H
sFilePath = sPath; ) lUS'I
sFileName = sName; 8n3]AOc'~-
this.nSplitter = nSpiltter; 4<Vi`X7[F
WJq>%<#
!Ubm 586!
} M5no4P<
jz8u'y[n7
vh\i ^
public String getSSiteURL() Qxz[
{ _r-LX"
return sSiteURL; akvi^]x
} |mtW)
?L }>9$"
ZN8j})lE
public void setSSiteURL(String value) y`RzcXblIZ
{ X9| Z?jJ
sSiteURL = value; +@ChZ
} ^$Y9.IH"
1h@qcom9K_
wlNL;W@w
public String getSFilePath() =7V4{|ESfy
{ ^ 9+ Qxv
return sFilePath; #}#m\=0
} O1v)*&NAI
}<WJR Y6j
htB7 j(
public void setSFilePath(String value) ]0D-g2!|A
{ `%Fp'`ZM$8
sFilePath = value; c+l1l0BA
} ;VLDXvGd
3A,N1OXG
Lip#uuuXXN
public String getSFileName() -`'|z+V
{ eV"%(<{
return sFileName; c~U0&V_`j
} Onx6Fy]L
_&, A
p8,=K<
public void setSFileName(String value) 'bx}[
{ })OS2F
sFileName = value; x/<ow4C
} v:SHaUS
0#NMNZ
i6paNHi*
public int getNSplitter() ,t 2CQ
{ P"NI> HM
return nSplitter; ~k34#j:J65
} Vs5 &X+k
<lB2Nv-,
]L~z9)
public void setNSplitter(int nCount) 3.YH7rN
{ L9/'zhiZBx
nSplitter = nCount; {APfSD_4
} w5z]=dN
} d_ =K (}eR
B<s+I#
.Vt|;P}
/* Mzg'$]N
**Utility.java #:" ]-u^
*/ ]MYbx)v)
package NetFox; 0c>>:w20D
"dCIg{j
Sp[9vlo8
public class Utility { v Z10Rb8
9]3l'
q2 7Ac;y
public Utility() :vi %7
{ {W?!tD43"
q[/g3D\G
8GxT!
} Vc'p+e|(
;s3@(OnjZ
//线程睡眠 08:K9zr
public static void sleep(int nSecond) CH+%q+I
{ +]t9kr
try{ 0(&uH0x
Thread.sleep(nSecond); T\wOGaCW
} Z2{$FN
catch(Exception e) 3Dc^lfn
{ *Iw19o-I
e.printStackTrace (); toF6 Z
} crd|r."
} ?Zv5iI
fx 08>r
//日志 RGV{KL
public static void log(String sMsg) _BG`!3U+
{ *QW.#y>"j
System.err.println(sMsg); 9^SrOW6~
} fo}@B&=4
tc;$7F ;
WV}pE~
public static void log(int sMsg) >VjtKSN
{ m$Tt y[0
System.err.println(sMsg); ]Gl_L7u`
} i_6wD
} p38s&\-kEN
J!rZskd
Rpcnpo
/* dkEnc
**TestMethod.java 7.5\LTM>9e
*/ uJ*|SSN~
package NetFox; nkkGJV!
x2i`$iNhmP
/9y'UKl7[
public class TestMethod { fv3)#>Dgp>
7Ph+Vs+h
9DXu*}
public TestMethod() ;c~DBJg'|
{ ///xx/weblogic60b2_win.exe BcGQpv&x
try{ Us9$,(3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8DrKq]&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A[d'*n[
SiteFileFetch fileFetch = new SiteFileFetch(bean); WY~}sE
fileFetch.start(); S67T:ARS
} [/t/694
catch(Exception e){e.printStackTrace ();} 6ud<B
NOmSLIgt7
Q^V`%+
} }Lwj~{
ZsPBs4<p
HNoh B4vt
public static void main(String[] args) o:Z*F0qm
{ M/sqOhg
new TestMethod(); ELNA-ZKp
} :S7yM8b`
} *t|j+*c}
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