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)); 9Le/'ovq
} v\r7.l:hf
for(int i=0;i<nEndPos.length-1;i++) 8kn]_6:3i
{ HCn]#
nEndPos = nStartPos[i+1]; `eA&C4oFOO
} u:qD*zOq
nEndPos[nEndPos.length-1] = nFileLength; ~L Bq5a
} VAG+y/q
} zN8&M<mTl
^`B##9g~
dcc%G7w
//启动子线程 >(1_Dn\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^~*[~
for(int i=0;i<nStartPos.length;i++) +p%5/smfs
{ #xJGuYdv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R)DNFc:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8 MACbLY
nStartPos,nEndPos,i); WPh |~]by<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5;i!PuL
fileSplitterFetch.start(); k(vEp]
} o )}<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !xx> lX5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \p=W4W/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `!>dbR&1
nEndPos = " + nFileLength); Jr*S2z<*
// fileSplitterFetch[nPos.length-1].start(); U{:(j5m
Z2pN<S{5
\w@_(4")Qb
//等待子线程结束 Rs(CrB/M
//int count = 0; H--*[3".
//是否结束while循环 q4#f *]
boolean breakWhile = false; Y|qixpP
9OO_Hp#|9
6pdl,5[x-
while(!bStop) Lb3K};SIV
{ 2 vJ[vsrFv
write_nPos(); 0qV*d
Utility.sleep(500); fG[3%e
breakWhile = true; DJ2]NA$Q*
*Yk8Mj^_h
e7)%=F/)
for(int i=0;i<nStartPos.length;i++) g cK"
{ N@du.d:
if(!fileSplitterFetch.bDownOver) 1p"EE~v
{ i2%m}S;D9
breakWhile = false; ,B/p1^;.
break; 4>wIF}\
} lVp~oZC6[
} h9OL%n 7m'
if(breakWhile) 0)]C&;}_M
break; SYW=L
^*UfCoj9Z
W$VCST
//count++; GO GXM4I
//if(count>4) G]NtX4'4
// siteStop(); >7Sl( UY-
} 6+f>XL#w
36A.h,~
oTV8rG
System.err.println("文件下载结束！"); 'Tan6Qa
} mEc;-b f
catch(Exception e){e.printStackTrace ();} g KmRjK
} `J7Lecgo
f[I'j0H%
pNf9
//获得文件长度 ]ieA?:0Hi
public long getFileSize() /KvPiQ%
{ Y" +1,?yH
int nFileLength = -1; sq(063l
try{ V<7K!<g)b
URL url = new URL(siteInfoBean.getSSiteURL()); eYX_V6c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !DUg"o3G>
httpConnection.setRequestProperty("User-Agent","NetFox"); %LZM5Z^
G mUs U{
w wRT$-!
int responseCode=httpConnection.getResponseCode(); W;}u 2GH
if(responseCode>=400) {$TB#=G
{ xS-nO_t 'E
processErrorCode(responseCode); l|tp0[
return -2; //-2 represent access is error wj5s5dH
} c:_i)":
<7-,`
LW 3J$Am
String sHeader; pmD-]0
w7?9e#>Z
=v`&iL~m
for(int i=1;;i++) MdboWE5i
{ 6{r[Dq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S^`9[$KH0
//Utility.log(in.readLine()); xr3PO?:
sHeader=httpConnection.getHeaderFieldKey(i); #2'&=?J1r
if(sHeader!=null) ^V,/4u
{ b0=AQ/:
if(sHeader.equals("Content-Length")) !J(,M)p!
{ *rKv`nva5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QM=436fq
break; v%~ViOgL\
} "/-v 9
} tYNt>9L|
else Nv]/L+i
break; cYn}we}7
} XlJux_LD:
} E_uH'E
catch(IOException e){e.printStackTrace ();} ^X'7>{7Io
catch(Exception e){e.printStackTrace ();} 'n.9qxY;
lc(iy:z@
)g^Ewzy^X
Utility.log(nFileLength); &_9eg
R:m=HS_
Y6;9j=[
return nFileLength; ?o'arxCxZn
} {#Cm> @')
+Z(VWu6
E004"E<E
//保存下载信息（文件指针位置） @<JQn^M
private void write_nPos() vrx3O
{ e1}0f8%
try{ n:)Y'52}
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3H%WB|
output.writeInt(nStartPos.length); &c ~)z\$
for(int i=0;i<nStartPos.length;i++) <"%h1{V
{ z{WqICnb
// output.writeLong(nPos); ,IATJs$E
output.writeLong(fileSplitterFetch.nStartPos); [kkcV5I-
output.writeLong(fileSplitterFetch.nEndPos); ^P`'qfZ
} ]>T/Gl1
output.close(); qiJ{X{lI
} r26Wysi~%
catch(IOException e){e.printStackTrace ();} YWF<2l.
catch(Exception e){e.printStackTrace ();} .Dxrc
} R;2 -/MT-
YHAg4eb8
nEr, jd~f
//读取保存的下载信息（文件指针位置） 7s3<}
private void read_nPos() K#m o+n5-;
{ 6E4L4Vb
try{ JwVv+9hh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); th|Q NG
int nCount = input.readInt(); aX:$Q }S
nStartPos = new long[nCount]; 6* w;xf
nEndPos = new long[nCount]; _ RT}Ee}Y
for(int i=0;i<nStartPos.length;i++) [wYQP6Cyy
{ mn` Ae=
nStartPos = input.readLong(); HEN9D/O=
nEndPos = input.readLong(); U%l{>*q
} 8G<.5!f7`N
input.close(); nJC}wh2d#
} b7mP~]V
catch(IOException e){e.printStackTrace ();} &T}e93]
catch(Exception e){e.printStackTrace ();} }$U6lh/Ep
} ]h@:Y]
OSU=O
Q)&Ztw<
private void processErrorCode(int nErrorCode) mj~CCokF{?
{ Y [S^&pF
System.err.println("Error Code : " + nErrorCode); FFGTIT# {"
} (^\i(cfu6Q
'5\1uB PKW
aR $P}]H
//停止文件下载 +M:Q!'
public void siteStop() |05LHwb>
{ @DR&e^Zz
bStop = true; %Kp}Wo6
for(int i=0;i<nStartPos.length;i++) (FHh,y~v
fileSplitterFetch.splitterStop(); )cXc"aj@s
z>~3*a9&
$i Tgv?.Q
} s<]l[Y>
} "'(4l 2.
//负责部分文件的抓取 LJx g
**FileSplitterFetch.java ,55`s#;
*/ !2}Q9a
package NetFox; 9 |Y?#oZ1
Mt>DAk
o}z}79Z
import java.io.*; U>XGJQ<NS
import java.net.*; $4pW#4/4
8Qh/=Ir
_i#Z'4?2E
public class FileSplitterFetch extends Thread { 50A_+f.7%
0Jr<>7Q1
X)+N>8o?N
String sURL; //File URL ^xrR3m*d
long nStartPos; //File Snippet Start Position i`;I"oY4
long nEndPos; //File Snippet End Position duCm+4,.
int nThreadID; //Thread's ID l?~h_8&fT
boolean bDownOver = false; //Downing is over 6G],t)<A'-
boolean bStop = false; //Stop identical :nt%z0_
FileAccessI fileAccessI = null; //File Access interface 3-D!ZS&
=%p{"<
Ycwb1e#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o hCPNm
{ P.0-(
this.sURL = sURL; `Ii>wb
this.nStartPos = nStart; .wywO|
this.nEndPos = nEnd; >xN^#$ng}
nThreadID = id; gUcE,L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CgWj9 [
} >KJ]\`2>)c
gMbvHlT
Z[VKB3Pb8
public void run() g@L4G?hLn
{ (Lp-3Xx
while(nStartPos < nEndPos && !bStop) t/CNxfY
{ 2_Qzc&"[ 4
%oo&M;
n_Z8%|h
try{ x$E l7=.
URL url = new URL(sURL); pFuQ!7Uk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $O#h4L_
httpConnection.setRequestProperty("User-Agent","NetFox"); kH'Cx^=c6h
String sProperty = "bytes="+nStartPos+"-"; NKRXY~zHh
httpConnection.setRequestProperty("RANGE",sProperty); ~Y(M>u.+!
Utility.log(sProperty); @tA.^k0`
= N#WwNC
$W2AiE[Wm
InputStream input = httpConnection.getInputStream(); C+Z"0\{o
//logResponseHead(httpConnection); @fwU%S[v
,F[mh
SO%5ts
byte[] b = new byte[1024]; 19EU[eb
int nRead; 2-~oNJqX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fjb2-K
{ W[jxfZD9v
nStartPos += fileAccessI.write(b,0,nRead); 2:abe
//if(nThreadID == 1) R[(,wY_1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H_Yy.yi
} =cQwR:):
ATU@5,9
<i5^izg
Utility.log("Thread " + nThreadID + " is over!"); ]kPco4
bDownOver = true; Dj|S
//nPos = fileAccessI.write (b,0,nRead); I4hr5M3
} (R,eWWF8~
catch(Exception e){e.printStackTrace ();} ?OSd8E+itM
} ]1K &U5p
} /H)g<YA
iw{n|&Y#`
cA*%K[9
//打印回应的头信息 {MS&t09Wh
public void logResponseHead(HttpURLConnection con) P+/L,u
{ gSC@uf
for(int i=1;;i++) Pzqgg43Xf
{ Z`W.(gua
String header=con.getHeaderFieldKey(i); ;KhYh S(q
if(header!=null) -nW{$&5AF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 75F&s,4+
Utility.log(header+" : "+con.getHeaderField(header)); 3"".kf,O5e
else HOw hl
break; _eF*8 /z
} ,%C$~+xjM
} (mEZ4yM
IkvH8E
(Cq-8**dY
public void splitterStop() zt8ZJlNK
{ C"sa.#}
bStop = true; m} V,+E
} IH0Uq_
0C7"*H0R
bhI8b/
} S$#Awen"@
n5b N/
H\S,^)drJ?
/* 29GiNy+ob
**FileAccess.java m4iR '~L}
*//文件访问(定位，写) ]mc,FlhU@
package NetFox; B5cTzY.h-
import java.io.*; ,R)[$n
OJ 2M_q)e
6?~pWZ&k_
public class FileAccessI implements Serializable{ 1~*_H_Q't
* n[6H
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =:b/z1-v
RandomAccessFile oSavedFile; #: F)A_Y
long nPos; 3lJK[V{'#'
A;g[G>J
pSAXp#g
public FileAccessI() throws IOException >8VJ!Kg4
{ Ua:EI!`
this("",0); t!~mbx+
} LKm5U6
BP7_o63/G
A=,m
public FileAccessI(String sName,long nPos) throws IOException YP6+o#==
{ )KNFS,5
oSavedFile = new RandomAccessFile(sName,"rw"); R6!3Y/Q@
this.nPos = nPos; ;R67a V,
oSavedFile.seek(nPos); 0QPipuP
} =m40{
wjl?@K
Kb}N!<Z*
public synchronized int write(byte[] b,int nStart,int nLen) 4b#YpK$7U
{ y0Tb/&xN
int n = -1; LC}]6
try{ (]pQ.3
oSavedFile.write(b,nStart,nLen); O-7 \qz
n = nLen; \h yTcFb
} koUH>J:
catch(IOException e) t^YDCcvoQ
{ b/ynCf8X
e.printStackTrace (); OS!47Z /q
} )yK!EK\
Wc)^@f[~<
w"D"9G
return n; n;MoMGnPh,
} a5)+5
2q#$?qs_b
Ft]sTA+C
} %jkd}D
t;*'p
`R^)<v*
/* T}zi P
**SiteInfoBean.java [-%oO
*/ w#o<qrpHf
package NetFox; 0 cQf_o
:9)>!+|'
B1GSZUd^?0
public class SiteInfoBean { )~J/,\
&K7g8x"x.
Lt*H|9
private String sSiteURL; //Site's URL Ah"RxA
private String sFilePath; //Saved File's Path !ine|NM
private String sFileName; //Saved File's Name )S`A+M K]
private int nSplitter; //Count of Splited Downloading File 9/'j<v6M
Mn=_lhWK
JRG7<s$
public SiteInfoBean() _[<I&^%
{//nSplitter的缺省值为5 86I".R$d
//default value of nSplitter is 5 > 4^U=T#
this("","","",5); xv)7-jlx
} !is8`8F8
ZpwB"%e$
G1D(-X4ALZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Um|:AT}`^
{ { u;ntDr
sSiteURL= sURL; 3(CUC
sFilePath = sPath; =e4,)Wd9&
sFileName = sName; ve>8vw2
this.nSplitter = nSpiltter; Ar\`OhR
#3qkG)
{u!,TDt*
} g'IS8@
*"E]^wCn
is6JS^Q
public String getSSiteURL() .Wr7?'D1M
{ yeW|Ux:
return sSiteURL; "c}bqoN
} vzVl2
6h5*b8LxA
oc15!M3$
public void setSSiteURL(String value) D3jP hPy.
{ UH)A n:9
sSiteURL = value; Z(V4"x7F
} 10a=[\ Q
F6fm{
F'Wef11Yz
public String getSFilePath() {}.c.W+
{ Z{e5 OJ
return sFilePath; 'SuYNA)
} 8]0R[kjD
,CCIg9Pt
M#:Mwa$
public void setSFilePath(String value) 3fGy
{ ?.4u'Dkn=
sFilePath = value; N!P* B$d
} ^+}<Q#y-
8sL7p4
WjA)0HL(
public String getSFileName() b]J_R"}
{ (5atU |8r
return sFileName; NE/3aU
} k1]?d7g$w
h'N,oDB)
]o_ Ps|
public void setSFileName(String value) ]A_)&`"Cb
{ z`/v}'d[X
sFileName = value; lfCoL@$6D
} ;KnnAZJ
Zaq:l[%
@ws3X\`<C
public int getNSplitter() Haturg
{ yvVs9"|0
return nSplitter; 9<xe%V=ki
} u[cbRn,W
a1s=t_wT
ne;,TJ\
public void setNSplitter(int nCount) &oAuh?kTq
{ i8dv|oa
nSplitter = nCount; 8 2_3|T
} PI }A')Nq.
} Ha;^U/0|
4$.4,4+
6W~F nJI
/* FzW(An&x2
**Utility.java aLP2p]
*/ Ii;~ xc
package NetFox; ]T+{]t
Mj[v _&N
tdEu4)6
public class Utility { '?q|7[SU
Yj;$hV8j(
cz.-cuD[iD
public Utility() @1rF9< 4g
{ R_(A&,
PF4Cs3m/
Ff.gRx
} .O~)zMx
(3W<yAM+
//线程睡眠 [ UQzCqV
public static void sleep(int nSecond) *-gS u
{ 8_W<BXW
try{ {L3lQ8Z
Thread.sleep(nSecond); jH\@Oc;7
} hYF<Wn3L
catch(Exception e) '|Cs!Zl
{ 0gxbo
e.printStackTrace (); ?e yo2:-$
} ij%\ld9kd
} MB:E/
+|\dVe.
//日志 1)M3*h3
public static void log(String sMsg) L{osh0
{ sexnO^s
System.err.println(sMsg); Av7bp[OD
} 3_ObCsJ#,
lO)p
t[7YMk
public static void log(int sMsg) O[Nc$dc
{ wB"&K;t
System.err.println(sMsg); 4km=KOx[
} |VTm5.23
} nB"q
"o%N`Xlx
%Wn/)#T|
/* ~E#>2Mh
**TestMethod.java 9fyk7~V
*/ |Q.t]TR'P
package NetFox; w#]%I+
mG\,T3/*
hyFq>XFo
public class TestMethod { TRG"fVR
GIt;Y
y~''r%]
public TestMethod() NSj}?hz
{ ///xx/weblogic60b2_win.exe g,mcxXO
try{ wbVM'E/&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [sbC6(z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :,6dW?mun6
SiteFileFetch fileFetch = new SiteFileFetch(bean); bvs0y7M='
fileFetch.start(); USJ4qv+-
} hAKyT~[n0
catch(Exception e){e.printStackTrace ();} ,~%Qu~\
-7hU1j~I
<HI5xB_
} hP,SvN#!2
[Kx_%Le
0}-&v+
public static void main(String[] args) %TvunV7NQS
{ @D Qg1|m
new TestMethod(); hekAics6S
} ngn%"xYX
} K-(,,wS
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