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)); ,A`d!{]5
} 0{^vqh.La
for(int i=0;i<nEndPos.length-1;i++) 1rKKph
{ 6E/>]3~!
nEndPos = nStartPos[i+1]; Se<]g$eK?5
} "[2CV!_
nEndPos[nEndPos.length-1] = nFileLength; l*>t@:2J
} $3<,"&;Ecs
} 6w(Mb~[n
+KgoLa
v,y nz'>)
//启动子线程 2+zE|I.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^!^6 |[
for(int i=0;i<nStartPos.length;i++) BZq_om6
{ 0T7(c-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !Ob
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %a=K:" oU[
nStartPos,nEndPos,i); >}Qj|05G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ec IgX_\
fileSplitterFetch.start(); 9pUvw_9MY
} fZ1v|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :f%FM&b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DX GClH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VN[C%C
nEndPos = " + nFileLength); 59mNb:<
// fileSplitterFetch[nPos.length-1].start(); <6QG7i
uMVM-(g%
%|E'cdvkX
//等待子线程结束 _Z?{&k
//int count = 0; @)PA9P |
//是否结束while循环 mAMi-9
boolean breakWhile = false; **_`AM~
D,q=?~
g?`g+:nug
while(!bStop) .w2QiJ
{ Go~bQ2*'(/
write_nPos(); BC*vG=a
Utility.sleep(500); _nu,ks+
breakWhile = true; Tlrr02>B{
IN=pki|.
^,u0kMG5l
for(int i=0;i<nStartPos.length;i++) |T?wM/
{ sqTBlP
if(!fileSplitterFetch.bDownOver) Ay)q %:qx
{ :K.%^ag=j
breakWhile = false; R}Pw#*B
break; io:g]g
} QK _1!t3
} 88}+.-3t$
if(breakWhile) 7'u<)V
break; dv=y,q@W
%pj6[x`@
PN9^ sLx=
//count++; r@N 0%JZZ
//if(count>4) j !^Tw.Ty
// siteStop(); {Hncm
} :VwU2
xg=}MoX
2VmQ%y6e"
System.err.println("文件下载结束！"); =B4,H=7Spf
} HUqG)t*c1
catch(Exception e){e.printStackTrace ();} Oop5bg
} VD[x}8ei
jv$Y]nf
RtVy^~=G
//获得文件长度 '=MaO@ @
public long getFileSize() fxfzi{}uj
{ r@C2zF7
int nFileLength = -1; P^m+SAAB
try{ z'@j9vT
URL url = new URL(siteInfoBean.getSSiteURL()); n8<o*f&&9>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dFY]~_P472
httpConnection.setRequestProperty("User-Agent","NetFox"); 3TUW+#[Gu
]jbQou@
GMmz`O XN
int responseCode=httpConnection.getResponseCode(); 9$,x^Qx
if(responseCode>=400) $r`K4g
{ h(}$-'g
processErrorCode(responseCode); dWHl<BUm
return -2; //-2 represent access is error v|5:;,I
} is=sV:j:
+mRFHZG
/H#- \r&r
String sHeader; 2|'v[
a*LT<N
YnnpgR.
for(int i=1;;i++) gcYx-gA}
{ >!+.M9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xlPUum-o
//Utility.log(in.readLine()); TDI8L\rr
sHeader=httpConnection.getHeaderFieldKey(i); wMy$T<:
if(sHeader!=null) m"Y;GzqQl
{ ~3}Gu^@
if(sHeader.equals("Content-Length")) e$F]t*)Xa
{ z;1y7W!v
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %bI(
break; |8I #`
} 8r '
} .DSn H6O
else (IXiwu
break; ^l1tQnj)7
} =H*}{'#
} shW$V93<
catch(IOException e){e.printStackTrace ();} U3r[ysf
catch(Exception e){e.printStackTrace ();} ( Lj{V}^
\)'nxFKqV
`|K,E
Utility.log(nFileLength); b?Wg|D
3L/qU^`
=ark?<E
return nFileLength; %M8Egr2|0
} "8K>Yu17
R'a%_sACj>
H <CsB
//保存下载信息（文件指针位置） ,4y'(DA
private void write_nPos() N;,?k.vU
{ 97:1L4w.(
try{ .0]4@'
output = new DataOutputStream(new FileOutputStream(tmpFile)); wUzQ`h2
output.writeInt(nStartPos.length); Hj ]$
for(int i=0;i<nStartPos.length;i++) PoMkFG6
{ /x.TF'Z*
// output.writeLong(nPos); Q,Tet&in )
output.writeLong(fileSplitterFetch.nStartPos); ]2G5ng' @
output.writeLong(fileSplitterFetch.nEndPos); <%eY>E
} >}QRMn|@H
output.close(); w?CbATQ
} 0P`wh=")
catch(IOException e){e.printStackTrace ();} `mPmEV<
catch(Exception e){e.printStackTrace ();} f@l6]z{.L
} ~ZU;0#
C("PCD
A7U'>r_.
//读取保存的下载信息（文件指针位置） CG'NC\x5
private void read_nPos() R`=3lY;
{ &SS"A*xg
try{ Lm+!/e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ) Kfk\
int nCount = input.readInt(); '$Jt}O
nStartPos = new long[nCount]; eydVWVN
nEndPos = new long[nCount]; ln.kEhQ3B
for(int i=0;i<nStartPos.length;i++) $mm =$.
{ r`u}n
nStartPos = input.readLong(); }_XW?^/8
nEndPos = input.readLong(); sh.xp8^)^>
} :1u>T3L.z
input.close(); khT&[!J{>
} ,CW]d#P|
catch(IOException e){e.printStackTrace ();} &_FNDJ>MCk
catch(Exception e){e.printStackTrace ();} `;fh<kv
} PK1j$&F
BmYU#h
8)/i\=N3;
private void processErrorCode(int nErrorCode) GkMNV7"m
{ gd<8RVA
System.err.println("Error Code : " + nErrorCode); oTZ?x}Z1
} "?,3O2t
SCeZt [
RAKQ+Y"nl
//停止文件下载 ANSvZqKh
public void siteStop() aKs!*uo0H
{ FtN1ZZ"<*
bStop = true; []Cvma1\
for(int i=0;i<nStartPos.length;i++) bGRI^ [8#+
fileSplitterFetch.splitterStop(); TRz~rW k
ezTu1-m
S-Va_t$
} /rp4m&!
} Bp\io$(%
//负责部分文件的抓取 C>cc!+n%H
**FileSplitterFetch.java R#~}ZUk2
*/ o^~6RZ
package NetFox; Gb61X6
O%9Cq}*
'R*gSqx~
import java.io.*; ($(6]?J(?7
import java.net.*; T(+F6d=1
V5rnI\:7
~C5iyXR
public class FileSplitterFetch extends Thread { $gDp-7
n ! qm
X@+:O-$
String sURL; //File URL e<5+&Cj
long nStartPos; //File Snippet Start Position HY#7Ctn3
long nEndPos; //File Snippet End Position :{4G=UbAI
int nThreadID; //Thread's ID 6bnAVTL5
boolean bDownOver = false; //Downing is over vVyO}Q`
boolean bStop = false; //Stop identical q" wi.&|
FileAccessI fileAccessI = null; //File Access interface !|_ CXm T|
MIa].S#
7^sU/3z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WAY<X:|We
{ &ukNzV}VW
this.sURL = sURL; *wt yyP@
this.nStartPos = nStart; qh$D;t1=
this.nEndPos = nEnd; {#QFDA
nThreadID = id; 2`5(XpYe
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7tAWPSwf
} mXc/sh")X
&o"Hb=k<
}=A6Jv(j
public void run() T.ub!,Y
{ rQ}4\PTi
while(nStartPos < nEndPos && !bStop) qIjC-#a=m
{ |L;'In
W/oRt<:E
N(vbo
try{ OpxVy _5,
URL url = new URL(sURL); R,Zuy(g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y@eHp-[
httpConnection.setRequestProperty("User-Agent","NetFox"); lk.Q6saI1
String sProperty = "bytes="+nStartPos+"-"; F/j=rs,*|D
httpConnection.setRequestProperty("RANGE",sProperty); @PwEom`a
Utility.log(sProperty); ?]fBds=
7P/j\frW
IX7d[nm39
InputStream input = httpConnection.getInputStream(); Ccz:NpK+
//logResponseHead(httpConnection); qjR;c& qR
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8g>jz 8
byte[] b = new byte[1024]; >o.u,
int nRead; 7vr)JT=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TeqFy(Dr
{ "]c:V4S#`A
nStartPos += fileAccessI.write(b,0,nRead); S-2xe?sb
//if(nThreadID == 1) ?Tuh22J{Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bDUGzezP<
} s+zb[3}
7]e]Y>wZap
6/4OFvL1
Utility.log("Thread " + nThreadID + " is over!"); "vLqYc4$
bDownOver = true; nOQ+oqM<
//nPos = fileAccessI.write (b,0,nRead); mf}?z21vD
} 3tXtt@Yy
catch(Exception e){e.printStackTrace ();} yWzvE:!)
} 83R"!w18
} @Jvw"=
q<c).4
[&NF0c[i
//打印回应的头信息 R$6Y\ *L[
public void logResponseHead(HttpURLConnection con) yE"hgdL
{ )W57n)]
for(int i=1;;i++) d1y(Jt
{ 8.k"kXU@n
String header=con.getHeaderFieldKey(i); IR/0gP
if(header!=null) 0@AK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $Z{ fKr
Utility.log(header+" : "+con.getHeaderField(header)); wCmwH=O
else ?\vJ8H[bD
break; E}NX+ vYF
} WDzov9ot
} NmB0CbB
!Z=`Wk5
g<,v2A
public void splitterStop() Eq.c;3
{ "#4PU5.
bStop = true; -D!F|&$
} I*lq0&
boN)C?"^h
*[.\S3K`
} 6Ir ?@O1'!
T$}<So|
42m`7uQ
/* 8 6L&u:o:
**FileAccess.java h)y"?Jj
*//文件访问(定位，写) :hMuxHr
package NetFox; )3)L
import java.io.*; mnil1*-c0
&q":o 'q
tOspDPSXX
public class FileAccessI implements Serializable{ 7FMHz.ZRE
%{}Jr`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3tr?-l[N\
RandomAccessFile oSavedFile; $ng\qJ"HF
long nPos; PI{sO |
}1_gemlf
Wb4sfP_
public FileAccessI() throws IOException aaaC8;.
{ tkuN$Jl
this("",0); u8?ceM^r
} R8],}6,;E}
zb;'}l;+
l>qCT
public FileAccessI(String sName,long nPos) throws IOException L3<XWpv
{ hlUF9}
oSavedFile = new RandomAccessFile(sName,"rw"); Nju7!yVM_
this.nPos = nPos; W1:o2 C7
oSavedFile.seek(nPos); ,Y`C7Px
} |Cen5s W&
H<NYm#a"
1/&j'B
public synchronized int write(byte[] b,int nStart,int nLen) P%/+?(?
{ -9aht}Z
int n = -1; 'm2,7]
try{ 5T
oSavedFile.write(b,nStart,nLen); ?L'k2J
n = nLen; S>"dUM
} ,#c-"xY
catch(IOException e) e,4!/|H:
{ =r_ SMTu
e.printStackTrace (); Mb<KZ_wYOX
} QPFpGS{d
g:2/!tujL
mB1)!
return n; rBny*!n
} BR0bf5T/
9s7B1Pf
Pu9.Uwx
} lZ.,"F@
Q`//HOM,
G)e 20Mst
/* k~q[qKb8y:
**SiteInfoBean.java [j![R
*/ <v2R6cj5
package NetFox; i5AhF\7F9
(=PnLP
>Y\4v}-
public class SiteInfoBean { st+Kz uK
BryMq !
ZR#UoYjupb
private String sSiteURL; //Site's URL PkVXn
private String sFilePath; //Saved File's Path }F3Z~
private String sFileName; //Saved File's Name zc2,Mn2
private int nSplitter; //Count of Splited Downloading File yqBu7E$X
Iy,)>V%iZV
Jz|(B_U
public SiteInfoBean() xv%}xeEV
{//nSplitter的缺省值为5 RV($G8U
//default value of nSplitter is 5 k[zf`x^
this("","","",5); ?.Kl/8ml
} zh4o<f:-
snK9']WXo
H~$|y9>qI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #`W8-w
{ XG[%oL
sSiteURL= sURL; -#i%4[v
sFilePath = sPath; 3{_+dE"9
sFileName = sName; d@l;dos),
this.nSplitter = nSpiltter; CjST*(,b
<y'ttxeS
Fj&vWj`*
} %(e=Q^=
_ Po9pZ
Ec[:6}
public String getSSiteURL() >N3{*W
{ MD On; Af>
return sSiteURL; A9R}74e4g
} 3n/L;T,X
Jg Xbs+.
Zg'[.wov
public void setSSiteURL(String value) 2 43DdIG$
{ /J6CSk
sSiteURL = value; -5qO}^i$a
} 1";~"p2(
6S&#8l
o _CVZ
public String getSFilePath() /;lk.-yU
{ *CG2sAeB
return sFilePath; m&%N4Q~X>
} m:^@AR1%d
Kr#=u~~M
]I]dwi_g)
public void setSFilePath(String value) _<~05Eh
{ '0=U+Egp
sFilePath = value; 4 '+)9&g
} @2u<Bh}}
J)-owu;
7]^Cg;EtM:
public String getSFileName() *\`C!r
{ jsG9{/Ov3
return sFileName; [:k'VXL
} _m&VdIPO
zZRqb/20
ysa"f+/
public void setSFileName(String value) 6RF01z|~_
{ ENmo^O#,u
sFileName = value; e}?t[aK4#
} P``hw=L
y#MLxm
a=J?[qrx
public int getNSplitter() CVUDN2
{ A1@-;/H3
return nSplitter; sDF J
} YU"Am !
226s:\d
&l.^UQ
public void setNSplitter(int nCount) @<2pYIi8
{ *p-Fn$7\n
nSplitter = nCount; }Q%>Fv
} L=p.@VSZ
} +-Dd*yD6<
c`>\R<Z ]
xvkof 'Q)
/* dOhV`8l
**Utility.java -`RJk(
*/ Y!`?q8z$G
package NetFox; V.4j?\#%
5[3hw4
GWW@8GNI
public class Utility { zZxP= c
T'V(%\w
]`NbNr]K
public Utility() *Z]| Z4Q/`
{ GWhZ Mj
Z:*U/_G
aw 7f$Fqk
} ZBXGuf
lfA BF
//线程睡眠 ^DH*@M
public static void sleep(int nSecond) 9,Mp/.T"\
{ k@~-|\ooG
try{ B -KOf
Thread.sleep(nSecond); 5bw]cv$i
} T/K.'92S
catch(Exception e) $i1A470C
{ \(CW?9)
e.printStackTrace (); }.'%gJrS
} miKi$jC}vq
} AWi87q
R',w~1RV'
//日志 zbR.Lb
public static void log(String sMsg) d3$<|mG$
{ Lr^xp,_n
System.err.println(sMsg); W>~%6K>p
} H>]z=w~
Pjy?&;GvT
A)#sh) }Q
public static void log(int sMsg) !$?@;}=
{ KFhn}C3 i
System.err.println(sMsg); YfalsQ8
} q!TbM"
} =4D_-Q
$O>@(K
Jv<)/Km`
/* Id*^H:]C#
**TestMethod.java >(CoXSV5
*/ 8.^U6xA
package NetFox; ;?!rpj
kziBHis!
a(~YrA%~
public class TestMethod { u s0'7|{q
=tNiIU
Tc(R-Wi
public TestMethod() {XXNl)%
{ ///xx/weblogic60b2_win.exe S=g-&lK
try{ <f6PULm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HH#i.s2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }^<zVdwp
SiteFileFetch fileFetch = new SiteFileFetch(bean); FNM"!z
fileFetch.start(); _PbfFY #
} Mh|`XO.5I
catch(Exception e){e.printStackTrace ();} w3N%J>4_E
&-:yn&f7
\i+h P1mz
} ,m?D\Pru
b1u'ukDP\
E?mp6R]}%
public static void main(String[] args) Q75^7Ga_
{ -9I%
new TestMethod(); \Sby(l
} gJxVU41
} c.Y8CD.tqL
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