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)); 4_?*@L1
} j'FBt8P'
for(int i=0;i<nEndPos.length-1;i++) TM$`J
{ 6.GIUM%D
nEndPos = nStartPos[i+1]; !rgdOlTR^
} iI%"]- 0@1
nEndPos[nEndPos.length-1] = nFileLength; wB0ONH[
} ed7Hz#Qc
} qL68/7:A
tPho4,x$
9Dy/-%Ut9
//启动子线程 `]g}M,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; affig
for(int i=0;i<nStartPos.length;i++) }^B=f_Ag
{ \o,`@2H+'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p\7(IhW@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'q=Ly?9
nStartPos,nEndPos,i); q P>Gre
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GvT'v0&+
fileSplitterFetch.start(); w.H\j9E l
} gj Ue{cb5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $+a2CZs!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cwA+?:Ry}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p[-buB]
nEndPos = " + nFileLength); EK}f-Xei
// fileSplitterFetch[nPos.length-1].start(); DvvjIYB~
zi}dQsy6
-|xyj2M
//等待子线程结束 g4*]R>f
//int count = 0; 20H$9M=}
//是否结束while循环 Flzl,3rW4
boolean breakWhile = false; *a4nd_!
Y$?<y
slMWk;fmD}
while(!bStop) *.0#cP7 "
{ w0^T-O`<
write_nPos(); ~ugK&0i[2
Utility.sleep(500); efF>kcIC
breakWhile = true; O486:tF
NbnuQPb'
#~^Y2-C#
for(int i=0;i<nStartPos.length;i++) I8 {2cM;
{ 9:tKRN_D
if(!fileSplitterFetch.bDownOver) `7zNVYur8
{ /xRPQ|
breakWhile = false; !jxz2Q
break; {!hA^[}|
} Jm8#M z
} #b4Pn`[
if(breakWhile) @l:\Ka~TS
break; u;*Wc9>sU
&Rx-zp&dJ
ISuye2tExq
//count++; +9mnxU>
//if(count>4) 64OgE!
// siteStop(); Vee`q.
} D=nuK25
'WG%O7s.
4X2/n
System.err.println("文件下载结束！"); ~Xg@,?Zr
} Yg6 f
catch(Exception e){e.printStackTrace ();} g2WDa'{L
} wZm=h8d
)_nc;&%w
n1xN:A
//获得文件长度 ?qt>;o|Ue
public long getFileSize() 8j}CP
{ 4W9#z~'
int nFileLength = -1; "7pd(p *C
try{ #Xc6bA&
URL url = new URL(siteInfoBean.getSSiteURL()); Q1Sf7)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X,<n|zp
httpConnection.setRequestProperty("User-Agent","NetFox"); ^ cn)eA
`AA[k
=%YU~
int responseCode=httpConnection.getResponseCode(); 5/v@VUzH
if(responseCode>=400) b_]14 v
{ 1e>,QX
processErrorCode(responseCode); Zv*Z^; X9
return -2; //-2 represent access is error MKYXYR
} OIa=$l43C
=kUN ^hb
(!U5B Hnd
String sHeader; iQ9jt
)0P>o]fWI
.h2K$(/
for(int i=1;;i++) 3!0Eh8ncI
{ F~dq7AS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~)#JwY
//Utility.log(in.readLine()); gNO<`9q
sHeader=httpConnection.getHeaderFieldKey(i); 0FFx
if(sHeader!=null) E{*~>#+
{ <[2]p\rj
if(sHeader.equals("Content-Length")) eM*@zo<-
{ j|&?BBa9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); shwKB 5
break; H1'`* }V
} ~bCn%r2
} L "L@4B
else zhI} p.
break; 3n/U4fn_
} 2!/_Xh
} ;9pOtr
catch(IOException e){e.printStackTrace ();} ~B%=g)w
catch(Exception e){e.printStackTrace ();} VrA9}"1x~*
\ qc8;"@
33_YZOy^j
Utility.log(nFileLength); 6<+R55
Oc;0*v[I
G l=dL<F
return nFileLength; `7P4O
} -<jb>8
qh/q<
*K6 V$_{S
//保存下载信息（文件指针位置） X 5LI
private void write_nPos() z./M^7v?
{ ;6I{7[
try{ ] }XK
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0sq1SHI{
output.writeInt(nStartPos.length); `J^J_s
for(int i=0;i<nStartPos.length;i++) 9KVeFl
{ =j 6amk-
// output.writeLong(nPos); AAkdwo
output.writeLong(fileSplitterFetch.nStartPos); @ba5iIt
output.writeLong(fileSplitterFetch.nEndPos); s%Q pb{
} ^IuHc_
output.close(); >+=)Q,|R
} \eE0Rnaf-
catch(IOException e){e.printStackTrace ();} 2+Z2`k]AC
catch(Exception e){e.printStackTrace ();} iKa}@U
} Cd.pMoS
O^I~d{M 5I
,qak_bP
//读取保存的下载信息（文件指针位置） &E$jAqc
private void read_nPos() IBY3QG
{ pO$`(+q[
try{ . \*Z:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kDJ5x8Q#
int nCount = input.readInt(); nJny9g
nStartPos = new long[nCount]; HHD4#XcU
nEndPos = new long[nCount]; '+NmHu:q
for(int i=0;i<nStartPos.length;i++) v9Oyboh(y
{ 4^VY
nStartPos = input.readLong(); F8?&Ql/hdz
nEndPos = input.readLong(); gEtDqq~y@
} "xlf6pm%
input.close(); uAR!JJ
} FfN==2:b
catch(IOException e){e.printStackTrace ();} HH3WZ^0>
catch(Exception e){e.printStackTrace ();} ehI*cf({
} Qw.""MLmN8
dRyK'Xr
0O?B!Jr]RM
private void processErrorCode(int nErrorCode) X&h4A4#P
{ w*r.QzCu,5
System.err.println("Error Code : " + nErrorCode); X~Uvh8O
} WS@b3zzN
GwV2`2
l}%!&V0
//停止文件下载 ?@l9T)fF
public void siteStop() j|9;") 1
{ "?V4Tl~uu
bStop = true; Qv,|*bf
for(int i=0;i<nStartPos.length;i++) D Y($
fileSplitterFetch.splitterStop(); ,)XT;iGQe
JQ'NFl9<
dfGdY"&
} ZPn`.Qc
} ]v@#3,BV
//负责部分文件的抓取 x&tad+T
**FileSplitterFetch.java C<2vuZD
*/ X^#48*"a
package NetFox; R>Fie5?
Q2PY( #
8HdmG{7.
import java.io.*; oJR0sbikP
import java.net.*; }8p;w T!
BD[XP`[{
xA#B1qbw
public class FileSplitterFetch extends Thread { 4hg]/X"H#
(1%u`#5n-N
/sH3Rk.>
String sURL; //File URL &@c=$+#C
long nStartPos; //File Snippet Start Position p-UACMN&c
long nEndPos; //File Snippet End Position TS)p2#
int nThreadID; //Thread's ID ]x?9lQ1&
boolean bDownOver = false; //Downing is over D|,d_W
boolean bStop = false; //Stop identical V{@<Z8sW#
FileAccessI fileAccessI = null; //File Access interface j/{F#auI
"{&\nt
eHi|_3A&*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mKtZ@r)u
{ (tP>z+
this.sURL = sURL; *j2P#et
this.nStartPos = nStart; EYd`qk3
this.nEndPos = nEnd; BS>|M}G)r
nThreadID = id; bgqN&J)Jr)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $.(%7[
} }]N7CWy
7qV_QZ!.
QKYIBX
public void run() y'xB? >|
{ 7w_`<b6
while(nStartPos < nEndPos && !bStop) Z_D8}$!
{ +,9I3Dq
xvQJTRk
3_B .W
try{ !v<r=u
URL url = new URL(sURL); )?joF)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l.\Fr+*ej
httpConnection.setRequestProperty("User-Agent","NetFox"); Cq?l>
String sProperty = "bytes="+nStartPos+"-"; {f3)!Pei`J
httpConnection.setRequestProperty("RANGE",sProperty); m'XzZmI
Utility.log(sProperty); Hu|NS{Ke-
HlBw:D(z:^
SJ^.#^)
InputStream input = httpConnection.getInputStream(); +|).dm
//logResponseHead(httpConnection); E:T<mI?d
{N[IjY
9kuL1tcY
byte[] b = new byte[1024]; >,Zjlkh3
int nRead; u^|XQWR$:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @>B#2t&
{ cBBc^SR
nStartPos += fileAccessI.write(b,0,nRead); /$'tO3
//if(nThreadID == 1) (]^9>3{|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BJ<hP9#
} |8c3%jve
wo$9$~(
}H!c9Y
Utility.log("Thread " + nThreadID + " is over!"); 4K[E3aA
bDownOver = true; YwQxN"
//nPos = fileAccessI.write (b,0,nRead); Cy4@\X%W
} Dr$k6kZ}'U
catch(Exception e){e.printStackTrace ();} uDay||7^g
} 28C/^4
} 6E{HNPMb>
IUAx*R
D3$PvX[f
//打印回应的头信息 @D^y<7(
public void logResponseHead(HttpURLConnection con) @bOhnd#W
{ Yw"o_
for(int i=1;;i++) }L>}_NV\
{ @X?DHLM
String header=con.getHeaderFieldKey(i); >K1)XP
if(header!=null) E#v}//
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z4b2t}
Utility.log(header+" : "+con.getHeaderField(header)); rQ(Aj
else 3ox%1x NA
break; I!dA{INN
} CO%7^}xSE,
} B^P)(Nu+
A&jkc'
E'j>[C:U
public void splitterStop() Xa=oryDt
{ U748$%}]
bStop = true; 8{#WF#
} YD H!Nl
*9y)B|P^
#wK {G)J
} vP`Sz}FU
ST5L O#5
Q&@Ls?pu
/* e) 42SL^s
**FileAccess.java Fm_^7|
*//文件访问(定位，写) u\ro9l
package NetFox; G|Rsj{2'
import java.io.*; a\ fG)Fqp
^[,Q2MHCT(
x^Q:U1
public class FileAccessI implements Serializable{ bGOOC?[UX
/W1!mih
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t6m3lq{
RandomAccessFile oSavedFile; m_zl*s*6
long nPos; .T 6NMIp*
=e](eA;
h:-ZXIv?
public FileAccessI() throws IOException QMLz
{ 1"YN{Ut;G
this("",0); 1fm4:xHH
} r/}q=J.
Atc9[<~WG
<K;
public FileAccessI(String sName,long nPos) throws IOException C]414Ibi
{ %V71W3>6WS
oSavedFile = new RandomAccessFile(sName,"rw"); !TvNT}4Z
this.nPos = nPos; H )hO/1m
oSavedFile.seek(nPos); L[lX?g?Ob
} z`$jxSLm
yiO!ZT
dv-L!C
public synchronized int write(byte[] b,int nStart,int nLen) M<^]Ywq*p
{ 7aRtw:PQn
int n = -1; _QBN/KE9
try{ V 6I77z
oSavedFile.write(b,nStart,nLen); fI"sdzu^
n = nLen; O2;FaASF
} <}t~^E,
catch(IOException e) J9eOBom8e<
{ iGB1f*K%x
e.printStackTrace (); *;t\!XDgp
} 0`c|ZzY
VK*Dm:G0
waI?X2
return n; 86Hg?!<i.
} .a2b&}/.d
( m/ujz
:B{Wf 2<z
} `NYu|:JK:
|_."U9!Z^
8C]K36q
/* fh_+M"Y0`
**SiteInfoBean.java 'yxN1JF
*/ O+x"c3@Z)D
package NetFox; $`j%z@[g
Zc9@G-
oC ?UGY~xL
public class SiteInfoBean { \4Uhc3
|j$r@
9d&@;&al
private String sSiteURL; //Site's URL ^POHQQ
private String sFilePath; //Saved File's Path V%h,JA
private String sFileName; //Saved File's Name p0*qv"lA
private int nSplitter; //Count of Splited Downloading File 2[|52+zhc
4> k"$l/:
/T_{k.
public SiteInfoBean() L$L/5/
{//nSplitter的缺省值为5 yPY}b_W
//default value of nSplitter is 5 '8%jA$o\g
this("","","",5); ;)~}/nR<a
} =LXjq~p
8tfM,.]_i
'41'Gn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .3 >"qv
{ |w5m2Z
sSiteURL= sURL; a+'k#m
sFilePath = sPath; n*A?>NV
sFileName = sName; 37apOK4+
this.nSplitter = nSpiltter; #($~e|
r{>Q{$Q
^h\(j*/#X
} #[f]-c(!
:eIi^K z[
Z8C~o)n9
public String getSSiteURL() 7Tb[sc'
{ tGE=!qk
return sSiteURL; Cj%n?-
} ;w/@_!~
Q,nJz*AJ
+3uPHpMB-
public void setSSiteURL(String value) T@wgWE<0y_
{ Emy=q5ryl
sSiteURL = value; Q XSS
} |I[/Fl:
"; 1@f"kw
P~ : N
public String getSFilePath() \?v?%}x
{ W4;/;[/L
return sFilePath; QC,fyw\
} x~Y{ {
H;nEU@>"Z
O&dBLh!G
public void setSFilePath(String value) {FQ@eeU
{ @E 8P>kq
sFilePath = value; @An}
} g.Tc>?~
(Bq^ D9
l1bkhA b
public String getSFileName() 3Fb9\2<H
{ \sBXS.
return sFileName; X[<%T}s#
} ho-#Xbq#g
6Hbu7r*tm
;,8 )%[
public void setSFileName(String value) WNY:HH
{ NnH]c+
sFileName = value; "1YwV~M5
} >?Duz+W)
VV;%q3}:
_ amP:h
public int getNSplitter() beaSvhPU
{ ({ O~O5k
return nSplitter; %pIP#y[4
} (xfh 9=.
;FQNO:NP
NbC2N)L4
public void setNSplitter(int nCount) +4$][3.
{ @XJ#oxM^
nSplitter = nCount; ?K+q~DzNSD
} ~NZL~p
} A XhP3B]
{dXTj7
N4#D&5I",
/* OlB9z
**Utility.java dz?On\66
*/ z&cM8w:
package NetFox; jDb"|l
;L,i">_%u[
'W,*mfB
public class Utility { a:8 MoH4
;4U"y8PVTh
l?QA;9_R'
public Utility() +OqEe[Wk#
{ ]#Cc7wa
ue^HhZ9
GE`1j'^-
} &|j0GP&
CT5s`v!s
//线程睡眠 N>Ih2>8t
public static void sleep(int nSecond) W]oa7VAq
{ 76bMy4re
try{ hxzA1s%~
Thread.sleep(nSecond); _p>F43%p
} ,-hbwd~M
catch(Exception e) n$`+03a
{ |p!($
e.printStackTrace (); ufCpX>lNF
} q}+zNeC
} _1Q6FI5iR
"={*0P
//日志 F^$;hMh%
public static void log(String sMsg) ?2l`%l5(
{ +%v1X&_\
System.err.println(sMsg); jQxhR
} O/|))H?C
U(0FL6sPC
d#TA20`
public static void log(int sMsg) K-~gIlbQ`
{ JO*/UC>"
System.err.println(sMsg); BPa,P_6(
} Fsm6gE`|n
} pU9.#O
5RvE ),
WQ 2{`'z
/* B2oKvgw
**TestMethod.java 'da 'WZG
*/ O!%T<2i3
package NetFox; rf-yUH]&S
}NoP(&ebz*
hf]m'5pb
public class TestMethod { .b+ix=:
SkMFJ?J/
4w~%MZA^
public TestMethod() p J_+n:_{
{ ///xx/weblogic60b2_win.exe ~uH_y-
try{ 04jvrde8-O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Cdib{y<ji
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ax>j3HKi
SiteFileFetch fileFetch = new SiteFileFetch(bean); m3BL
fileFetch.start(); 5L:-Xr{
} jQzl!f1c3
catch(Exception e){e.printStackTrace ();} Db<#gH
@J&korU
X3a9-
} 'prHXzi(h
%0}^M1
]VxC]a2
public static void main(String[] args) Y*$>d/E
{ I-Z|FKh_C
new TestMethod(); vue^bn
} * eC[74Kng
} MW6z&+Z
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