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)); U9T}iI
} $\*Z
for(int i=0;i<nEndPos.length-1;i++) glCpA$;VPu
{ az![u)
nEndPos = nStartPos[i+1]; 4GI3|{
} F%a&|X
nEndPos[nEndPos.length-1] = nFileLength; D"aK;_W@h
} Htr]_<@
} s9"X.-!
o_Z9\'u
ZqrS]i@$
//启动子线程 ,gNZHKNq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u-&V, *3l
for(int i=0;i<nStartPos.length;i++) Kkovp^G
{ aHu0z:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A z@@0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :|kO}NGM
nStartPos,nEndPos,i); ;b65s9n^b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @~s5{4
fileSplitterFetch.start(); dakHH@Q
} ;UgwV/d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @k;65'"Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VD&wO'U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Drtg7v{@\
nEndPos = " + nFileLength); OKm,iIp]
// fileSplitterFetch[nPos.length-1].start(); ?bM%#x{e
Uf+y$n-
TYD( 6N
//等待子线程结束 !m:WoQ/
//int count = 0; LE{@J0r#n
//是否结束while循环 Sak^J.~G[
boolean breakWhile = false; ;6R9k]5P%
kJ"rRsK
kwUUvF7w
while(!bStop) 9Br+]F_i
{ g7?[}?]3"p
write_nPos(); 8K9HFT@yV
Utility.sleep(500); GC# [&>L
breakWhile = true; J?TCP%
Xh}q/H<
USEmD5q
for(int i=0;i<nStartPos.length;i++) {M:/HQo
{ SujEF`"
if(!fileSplitterFetch.bDownOver) H0inU+Ih
{ PTe$dPB
breakWhile = false; 5P<1I7d
break; 'fK=;mM
} [sG`D-\P[
} gYN;Fu-9Z
if(breakWhile) XGR63hXND
break; KB~1]cYMp
,d/$!Yf
{@L{l1|0
//count++; gQik>gFr
//if(count>4) !bLCha\
// siteStop(); V^FM-bg%9
} )G/=3;!
ESoqmCJjb:
i#YDdz
System.err.println("文件下载结束！"); <H]PP6_g:
} ;DX{+Z[
catch(Exception e){e.printStackTrace ();} Q(N'Oj:J
} 0_je@p+$
ynra%"sd
"UD)3_R
//获得文件长度 0y<9JvN$9
public long getFileSize() 9Oj b~
{ ,9^ 5
int nFileLength = -1; [wSoZBl
try{ U7fpaxc-
URL url = new URL(siteInfoBean.getSSiteURL()); YhglL!pC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l2W+VBn6
httpConnection.setRequestProperty("User-Agent","NetFox"); }` `oojz
PT,*KYF_O"
,e$RvFB
int responseCode=httpConnection.getResponseCode(); <hy!B4
if(responseCode>=400) 8bMw.u=F
{ m8L %!6o
processErrorCode(responseCode); (421$w,B%
return -2; //-2 represent access is error M6cybEk`
} n5xG4.#G
anz7ae&P'K
`::j\3B&Y-
String sHeader; Us "G X_
Ap\]v2G
3@eI?(N
for(int i=1;;i++) ~7}no}7
{ as3uz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9VaSCB
//Utility.log(in.readLine()); |af<2(d
sHeader=httpConnection.getHeaderFieldKey(i); ;QuxTmWp^
if(sHeader!=null) 6k,@+@]t.
{ 0|va}m`<3G
if(sHeader.equals("Content-Length")) nq7)0F%e
{ >/.jB/q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J.2BBy
break; Yy[=E\z
} ^+~$eg&js
} uq:'`o-1
else uJ=&++[
break; ArX*3
} )rA\+XT7
} =#TQXm']Gi
catch(IOException e){e.printStackTrace ();} Jnt r"a-4
catch(Exception e){e.printStackTrace ();} tMf5TiWu@
K'e!BZm6Q
"[A&S!
Utility.log(nFileLength); [uie]*^
j }^?Snq
rf$[8d
return nFileLength; \2@9k`
} J=^5GfM)J
ND9;%<80
{XhpxJ__
//保存下载信息（文件指针位置） )}w-;HX
private void write_nPos() 2s 9U&
{ 'uUa|J1mu
try{ Jz;`L3m
output = new DataOutputStream(new FileOutputStream(tmpFile)); zSsogAx
output.writeInt(nStartPos.length); *qMjoP,
for(int i=0;i<nStartPos.length;i++) W#b++}S
{ mMhe,8E&
// output.writeLong(nPos); ;XYfw)
output.writeLong(fileSplitterFetch.nStartPos); \hzx?
output.writeLong(fileSplitterFetch.nEndPos); jAt65a
} jq/{|<0
output.close(); mn<ea&
} v Ma$JPauI
catch(IOException e){e.printStackTrace ();} 71&`6#
catch(Exception e){e.printStackTrace ();} NVC$8imip
} Yic'p0< ?V
-IV-"-6(
+xmZK<{<
//读取保存的下载信息（文件指针位置） Git2Cet
private void read_nPos() SR)@'-Wd
{ '?fn} V
try{ Yu^}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1^;&?E
int nCount = input.readInt(); <* PjG}Z.
nStartPos = new long[nCount]; xi\uLu?i
nEndPos = new long[nCount]; hi]\M)l&x
for(int i=0;i<nStartPos.length;i++) 6B?1d /8V
{ 0j/i):@
nStartPos = input.readLong(); v#IZSBvuQK
nEndPos = input.readLong(); oU 8o;zk0
} Ox/va]e7"
input.close(); K&Q0]r?
} v:j4#pEWD
catch(IOException e){e.printStackTrace ();} P|)SXR
catch(Exception e){e.printStackTrace ();} Sag\wKV8
} VHws9)
tQ?}x#J
e''Wm.>g(+
private void processErrorCode(int nErrorCode) ':]w
{ w@f_TG"Vt
System.err.println("Error Code : " + nErrorCode); zjJyc?
} WUi7~Ei}
%}&9[#
L'h'm{i
//停止文件下载 {la^useg[
public void siteStop() R?\8SdJ
{ Un[#zh<4
bStop = true; BQ&h&57K
for(int i=0;i<nStartPos.length;i++) /L[:C=u
fileSplitterFetch.splitterStop(); }`^<ZNkb/
`}Hnj*
1$2Rs-J
} CUw 9aH
} 1r w>gR
//负责部分文件的抓取 qOa-@MN
**FileSplitterFetch.java oq<#
*/ +V\NMW4d
package NetFox; )'<zC
&c@I4RV|q
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import java.io.*; ?,),%JQ
import java.net.*; ]g+(#x_.?
IweQB}d
qx? lCz a"
public class FileSplitterFetch extends Thread { Cw^)}23R
EGMcU|yL
Yc5$915
String sURL; //File URL O "h+i>|l
long nStartPos; //File Snippet Start Position n:!J3pR
long nEndPos; //File Snippet End Position I2l'y8)d
int nThreadID; //Thread's ID a+BA~|u^
boolean bDownOver = false; //Downing is over Em.?
boolean bStop = false; //Stop identical W]*wxzf!5z
FileAccessI fileAccessI = null; //File Access interface =XS'V*
wYawG$@_
p9sxA|O=y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4-n.4j|
{ bKaV]Uy
this.sURL = sURL; SO&;]YO
this.nStartPos = nStart; \)"qN^we
this.nEndPos = nEnd; ?%0i,p@<
nThreadID = id; QY fS-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !c`1~a!
} jKQP0 t-
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nW%c95E
public void run() +1623E
{ Gsh2
while(nStartPos < nEndPos && !bStop) 3a S>U #
{ *:_hOOT+[
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nb!m>0*/
try{ Qqaf\$X
URL url = new URL(sURL); QtzHr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bcE DjLXq
httpConnection.setRequestProperty("User-Agent","NetFox"); ~5#7i_%@E}
String sProperty = "bytes="+nStartPos+"-"; gddGl=rm
httpConnection.setRequestProperty("RANGE",sProperty); Y{'G2)e
Utility.log(sProperty); Stw6%T-
y|mR'{$I
Q&\k"X1
InputStream input = httpConnection.getInputStream(); v>P){VT
//logResponseHead(httpConnection); 1wM p3
1|89-Ii]
5~? J
byte[] b = new byte[1024]; cK } Qu
int nRead; n(+:l'#HJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pVY.&XBZ$
{ 5VcYdu3
nStartPos += fileAccessI.write(b,0,nRead); ']NM_0
//if(nThreadID == 1) O#|E7;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &pAT
} pQhv3F
w{qYP
Vqr&)i"b$
Utility.log("Thread " + nThreadID + " is over!"); eyWwE%
bDownOver = true; DQ}]'*@?
//nPos = fileAccessI.write (b,0,nRead); iB`m!g6$
} oAx0$]+%V)
catch(Exception e){e.printStackTrace ();} WQ]pg "
} ] ge-b\
} `F@yZ4L3S
M/qiA.C@W
N@>S>U8C
//打印回应的头信息 EIfrZg7R
public void logResponseHead(HttpURLConnection con) o_5@R+&
{ s'^#[%EgB
for(int i=1;;i++) &Hqu`A/^
{ rG]Xgq"
String header=con.getHeaderFieldKey(i); _V?Q4}7d/
if(header!=null) ( FRf.mv{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l]Sui_+ZU
Utility.log(header+" : "+con.getHeaderField(header)); 8K/lpqw
else D.e*IP1R
break; {m?x},
} $} Myj'`r
} k|D!0^HE[
.,,73"
.wSAysiQ|P
public void splitterStop() v>5F[0gE
{ GXl?Zg
bStop = true; [`lAc V<
} ;rKYWj>IR
AQ5v`xE4
ao!r6:&v$e
} 5 $J
@6SSk=9_S
ik*_,51Zj
/* ,L;vN6~
**FileAccess.java ;<A/e
*//文件访问(定位，写) 5dk,!Cjg
package NetFox; YovY0nO
import java.io.*; v=>Gvl3&U
NsHveOK1.
;=OH=+Rl
public class FileAccessI implements Serializable{ ^xwFjQXx
(Wqhuw!u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (YOgQ)},
RandomAccessFile oSavedFile; I .ty-X]
long nPos; z"#.o^5
!)=o,sVA
CmOb+:4@K
public FileAccessI() throws IOException Ul Iw&U
{ +q$|6?
this("",0); p rgjU
} 3@L%#]xwi
Cs{f'I
h~p}08
public FileAccessI(String sName,long nPos) throws IOException jHCKV
{ |_*$+
oSavedFile = new RandomAccessFile(sName,"rw"); Kc0OLcu^d
this.nPos = nPos; [4j;FN Fa
oSavedFile.seek(nPos); v3Yj2LSqx
} Hi9z<l=$
;>9pJ72r
rE:>G]j6
public synchronized int write(byte[] b,int nStart,int nLen) {)qP34rM
{ ~tvoR&{I
int n = -1; GB3B4)cX4Y
try{ : 4WbDeR
oSavedFile.write(b,nStart,nLen); l0{DnQA>I
n = nLen; P}`1#$
} kVv <tw
catch(IOException e) xF;v 6d
{ 1\0@?6`^
e.printStackTrace (); !%r`'|9y
} 3~ZVAg[c
lv*uXg.k^
9,CC1f
return n; . $YF|v[=
} F.D1;,x
c^IEj1@}'?
us%RQ8=k
} [udV }
Y +54z/{
Ui!|!V-
/* gUA}%YXe
**SiteInfoBean.java nh)R
*/ `F8;{`a
package NetFox; w.p'Dpw
t8 "-zd8
"lf3hWGw
public class SiteInfoBean { VYo;[ue([
dy?|Q33Y"
XH$|DeAFM
private String sSiteURL; //Site's URL q&T'x> /
private String sFilePath; //Saved File's Path f*}E\,V"&
private String sFileName; //Saved File's Name CJ
private int nSplitter; //Count of Splited Downloading File t}*!UixE
(t$/G3E
cV,Dl`1r
public SiteInfoBean() Po.BcytM
{//nSplitter的缺省值为5 |9]K:A
//default value of nSplitter is 5 Tpx,41(k
this("","","",5); 98'XSL|
} %0]b5u
[_b='/8
}Xv1KX'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1iL xXd
{ }F6b ]
sSiteURL= sURL; G| oG:
sFilePath = sPath; )%w8>1}c
sFileName = sName; DW&')gfQ
this.nSplitter = nSpiltter; yuDd% 1k
%5?-g[
AiK4t-
} BrMp_M
B-'BJ|*4I
8k?L{hF|nW
public String getSSiteURL() %MZDm&f>Kk
{ O \8G~V 5"
return sSiteURL; Ia:puks=
} mIEaWE;E"
9R"N#w.U]
<L/vNP
public void setSSiteURL(String value) sNmC#,
{ \'tz|
sSiteURL = value; $'{`i5XB
} b:cK>fh0_
~{Rt4o _W
KVpAV$|e
public String getSFilePath() SLOYlRGCi
{ +{i"G,3
return sFilePath; ef:$1VIBda
} ]G~N+\8]U
QYw4kD}
>E ;o"
public void setSFilePath(String value) edk9Qd9
{ _XNR um4
sFilePath = value; <sYw%9V
} TxxB0
/ !
T^;Jz!e
public String getSFileName() |SukiXJZF
{ f<4q]HCa
return sFileName; )X!DCL:16
} {^5<{j3e
)k] !u
^ R^N`V
public void setSFileName(String value) B "F`OS[
{ ^O Xr: P
sFileName = value; JKi@Kw
} ;4v}0N~.
P9mxY*K)%5
"q>I?UcZ
public int getNSplitter() gXLZ)>+A+
{ \{=`F`oB=
return nSplitter; m<,G:?RM
} 3et2\wOX1x
V&j.>Y
C\^<v&
public void setNSplitter(int nCount) A.C278^O8
{ imCl{vt(kj
nSplitter = nCount; xnuv4Z}]t
} mc=!X
} IL2Gsj)M
QDgEJ%U-
|od4kt
/* U[e8K
**Utility.java kPX2e h
*/ pM'IQ3N
package NetFox; 5v>{Z0TE[6
qwNKRqT
G9y12HV
public class Utility { dMs39j
{F6dSF`
:n>ccZeMv
public Utility() *[1u[H9Cv
{ +=*m! 7Mr
[T[9*6Kt
6:@t=C
} e(;`9T
'UvS3]bSYW
//线程睡眠 @wdB%
public static void sleep(int nSecond) qzlMn)e
{ zhX`~){N6
try{ HMS9y%zl/
Thread.sleep(nSecond); :OQ:@Yk
} $,QpSK`9i
catch(Exception e) E4v_2Q -w
{ #u<oEDQ
e.printStackTrace (); 51ajE2+X&
} U_}A{bFG
} sAD P~xvU
K)Xs L
//日志 {Sr=SE
public static void log(String sMsg) 'K@{vB
{ A?;8%00
System.err.println(sMsg); [N95.aD
} q~Q)'*m
>SxZ9T|%
m]=oaj@9
public static void log(int sMsg) `l gjw=
{ )_c=mT
System.err.println(sMsg); |1QbO`f/F
} BheEI;}
} R0hctT1j
5e/qgI)M5
l@tyg7CwY
/* lA.;ZD!
**TestMethod.java aO^:dl5
*/ wSJ]3gJM`
package NetFox; g<rKV+$6
RFn0P)9&
=(|xU?OL
public class TestMethod { C7jc6(>m
JwI`"$>w
=,C9O
public TestMethod() 3u?`q%Y-e
{ ///xx/weblogic60b2_win.exe I>kiah*
try{ hM36QOdm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /J[H5uA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m,@1LwBH
SiteFileFetch fileFetch = new SiteFileFetch(bean); F[7Kw"~J
fileFetch.start(); ( *9Ip
} M)`HK .
catch(Exception e){e.printStackTrace ();} da00p-U
hSkc9jBF
R*Xu(89
} sMz^!RX@
(!0j4'
kh<pLI>$h
public static void main(String[] args) 9b"9m*gC
{ Wiq{wxe
new TestMethod(); 0j{F^rph
} joChML_
} C?[a3rNH(
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