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)); y? co|
} ^) s2$A:L
for(int i=0;i<nEndPos.length-1;i++) jXMyPNTK
{ s91JBP|B7
nEndPos = nStartPos[i+1]; x UD-iSY
} )d>!"JB-
nEndPos[nEndPos.length-1] = nFileLength; aVd,xl
} @Rw!'T
} D N*t~Z3[
_zwUE
` 5C~
//启动子线程 qC?:*CXH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E\4 +_L_j
for(int i=0;i<nStartPos.length;i++) x a06i#
{ yT,.z 0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ..R-Ms)k=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r'*}TM'8
nStartPos,nEndPos,i); qm8&*UuKJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w&KK3*=""
fileSplitterFetch.start(); 1wP-
} k'5?M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4BKI-;v$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n;T7=1_"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iS<I0\D
nEndPos = " + nFileLength); 7[}xP#Z
// fileSplitterFetch[nPos.length-1].start(); DY?Kfvef
" _ka<R..
u9EgdpD
//等待子线程结束 jYhB +|
//int count = 0; 5)MS~ii
//是否结束while循环 5qP:/*+
boolean breakWhile = false; F;<xnC{[
ML>[^F
fk x \=
while(!bStop) /Bm( `T
{ 9Q+'n$s0^
write_nPos(); UaB @
Utility.sleep(500); >\Ww;1yV
breakWhile = true; t8+X%-r
PJL=$gBgKk
AQ[GO6$,%H
for(int i=0;i<nStartPos.length;i++) X'qU*Eo
{ _ "VkGG
if(!fileSplitterFetch.bDownOver) n@,G8=J?
{ 7w6cwHrL@
breakWhile = false; csW43&
break; FK5<6n,U
} _zwG\I|Q
} pv Gf\pu
if(breakWhile) S-|)QGxV6
break; 65aK2MS@
q;][5
xM&Wgei]10
//count++; /VN f{p
//if(count>4) CyXRi}W.
// siteStop(); #/<&*Pu5t
} TO?R({yx*
M 4?ig}kh
1R1z
System.err.println("文件下载结束！"); m4l& eEp
} GfmI<{da
catch(Exception e){e.printStackTrace ();} Tw;3_Lj
} `u teg=
xY^%&n
V^Q#:@0
//获得文件长度 O#S;q5L@
public long getFileSize() &N\jG373
{ s)6U_
int nFileLength = -1; ov_j4j>6P
try{ z;|A(*Y
URL url = new URL(siteInfoBean.getSSiteURL()); K+3IWZ&+dG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ='s(|
httpConnection.setRequestProperty("User-Agent","NetFox"); ~^r29'3
|6K+E6H
:<bB?N(
int responseCode=httpConnection.getResponseCode(); {_ i\f ]L
if(responseCode>=400) W;!}#o|%s
{ e'~J,(fB
processErrorCode(responseCode); ,>0*@2
return -2; //-2 represent access is error c*L0@Ak%
} /2=#t-p+
8{^WY7.'
,0~n3G
String sHeader; uF9C-H@:
%}Ss,XJ
pgQV/6
for(int i=1;;i++) QD:{U8YbF$
{ y)W@{@{kl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pEIRh1
//Utility.log(in.readLine()); oPXkYW
sHeader=httpConnection.getHeaderFieldKey(i); &3J_^210
if(sHeader!=null) XkXHGDEf1
{ ToXki,
if(sHeader.equals("Content-Length")) Vr^n1sgE}r
{ N343qU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8&?s#5zA
break; {MCi<7j<?
} X.f>'0i
} s'E2P[:
else Rv$[)`&T
break; C/vIEYG4
} $o0iLFIX/
} WJkZ!O$"j
catch(IOException e){e.printStackTrace ();} V )x$|!(
catch(Exception e){e.printStackTrace ();} !Wy6/F@Z
vY${;#~|
mpuq 9)6
Utility.log(nFileLength); %_RQx2
j3{I /m
6@{(;~r
return nFileLength; ]* F\"C@
} aWWU4xe
TDFkxB>
Po__-xN>Q
//保存下载信息（文件指针位置） AX;8^6.F3
private void write_nPos() h_:C+)13`x
{ g`vny)\7/
try{ >VP=MbN
output = new DataOutputStream(new FileOutputStream(tmpFile)); b[t>te
output.writeInt(nStartPos.length); {*0<T|<n
for(int i=0;i<nStartPos.length;i++) m#PY,y
{ ~sl{|E
// output.writeLong(nPos); pQ=>.JU
output.writeLong(fileSplitterFetch.nStartPos); a(kg/s
output.writeLong(fileSplitterFetch.nEndPos); j9?}j#@
} 4)h]MOZ
output.close(); dJ2Hr;Lc
} V5sg#|&
catch(IOException e){e.printStackTrace ();} 7n8~K3~;
catch(Exception e){e.printStackTrace ();} ?Z Rs\+{vG
} Rot@x r7Hc
"?ucO4d
"HElB9
//读取保存的下载信息（文件指针位置） *1p|5!4c
private void read_nPos() NdtB1b
{ uC+V6;
try{ PP;}e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e+$p9k~
int nCount = input.readInt(); Rn`x7(WA
nStartPos = new long[nCount]; Sp@^XmX(S
nEndPos = new long[nCount]; tZ=E')!\
for(int i=0;i<nStartPos.length;i++) k9 "[H'
{ {sihus#Q
nStartPos = input.readLong(); Pz>s6 [ob
nEndPos = input.readLong(); E*.{=W }C
} r=5{o1"
input.close(); Mr;E<Lj ^K
} ,Sq/y~
catch(IOException e){e.printStackTrace ();} Z*y`R XE
catch(Exception e){e.printStackTrace ();} ROg(U8 N
} T]t+E'sQ
J7=+
_,xc[ 07
private void processErrorCode(int nErrorCode) i@P)a'W_
{ jhXkSj
System.err.println("Error Code : " + nErrorCode); mL{B!Q
} xC*6vH]?
0vEoGgY0*:
^T ?RK"p
//停止文件下载 1<BX]-/tP
public void siteStop() O4r0R1VQM
{ oFy=-p+C
bStop = true; /tP|b_7O
for(int i=0;i<nStartPos.length;i++) +W:=e,=
fileSplitterFetch.splitterStop(); U7`A497Z
0'V5/W
D2](da:]8)
} (eCJ;%%k
} 2"Ecd
//负责部分文件的抓取 \R|4( +]x
**FileSplitterFetch.java gZLP\_CL
*/ "OQ^U_
package NetFox; gCioq.
O\E/. B
,_Z5m;
import java.io.*; a=DcZ_M
import java.net.*; * mOo@+89
P%{^i]
NdL,F;^
public class FileSplitterFetch extends Thread { GliwY_
jDy-)2<
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String sURL; //File URL Po ZuMF
long nStartPos; //File Snippet Start Position FrTi+& <
long nEndPos; //File Snippet End Position }dp=?AFg
int nThreadID; //Thread's ID EQf[,
boolean bDownOver = false; //Downing is over ep2k%?CX 1
boolean bStop = false; //Stop identical x$1]M DAGb
FileAccessI fileAccessI = null; //File Access interface ]}U*_rM:
n^z]q;IN2.
Q^ pmQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W_kHj}dj,p
{ Ag&0wN+jTM
this.sURL = sURL; k9L?+PD
this.nStartPos = nStart; A9wh(P0\
this.nEndPos = nEnd; cm?\ -[cV
nThreadID = id; _(h&7P9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $lLz3YS
} nq6@6GRG
VO$ iNK
{5F-5YL+>
public void run() @^T1XX
{ l y(>8F
while(nStartPos < nEndPos && !bStop) T;,cN7>>O
{ ]`kmjn
huJ&]"C
+xrr?g
try{ -?mfE+kt
URL url = new URL(sURL); cUvz2TK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qNYN-f~@,
httpConnection.setRequestProperty("User-Agent","NetFox"); @>p<3_Y1
String sProperty = "bytes="+nStartPos+"-"; {buo^kgj`]
httpConnection.setRequestProperty("RANGE",sProperty); .w0s%T,8}^
Utility.log(sProperty); ~g5[$r-u-u
n2oz"<?$S
~S8*t~
InputStream input = httpConnection.getInputStream(); w]]8dz
//logResponseHead(httpConnection); ApAO/q
MBqt&_?K
>AcrG]
byte[] b = new byte[1024]; LUqB&,a}
int nRead; prTw'~(B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Mdl{}P0)
{ )pq;*~IBI
nStartPos += fileAccessI.write(b,0,nRead); -(f)6a+H
//if(nThreadID == 1) `NgAT 3zq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5 N#3a0)
} QNpqdwu%h
=y0C1LD+
yuat" Pg
Utility.log("Thread " + nThreadID + " is over!"); HbXPok
bDownOver = true; `/EGyN6X
//nPos = fileAccessI.write (b,0,nRead); :9^;Qv*
} a{ ?`t|
catch(Exception e){e.printStackTrace ();} Fsif6k=4
} L#+q]j+
} (Q.waI
A?-oL='
(2:/8\_P
//打印回应的头信息 sB c (gr
public void logResponseHead(HttpURLConnection con) .ys6"V|31
{ %<an9WMF
for(int i=1;;i++) W9D86]3Y
{ 6^%68N1k
String header=con.getHeaderFieldKey(i); S"OR%
if(header!=null) Z|5?7v;h5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Jme!Oaa
Utility.log(header+" : "+con.getHeaderField(header)); d5D$&5Ec
else gG-BVl"59
break; BV>\ McI+
} dt`{!lts'
} [&&1j@LQ*
ReM=eS
bpKZ3}U
public void splitterStop() rld67'KcE
{ #ZYVc|sT+
bStop = true; ^!9~Nwn
} Bh=u|8yxc
DsT>3
{a4z2"\A
} )FpZPdN+h
t5#rps\;
3>R#zJf
/* ],RdySN&
**FileAccess.java ,)iKH]lY=
*//文件访问(定位，写) mw='dFt
package NetFox; O }(VlR2
import java.io.*; 6bBB/yd
*g[^.Sg
)w0AC"2O~
public class FileAccessI implements Serializable{ 1. rj'
[BT/~6ovrZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V}SBuQp"
RandomAccessFile oSavedFile; H Ge0hl[n
long nPos; zJ)*Z,7
Dg} Ka7H
Pri`K/
public FileAccessI() throws IOException 6Qx#%,U^ J
{ \o/n
this("",0); 4(1(e
} H<}^'#"p
~R&;v3
\l.-eu'O
public FileAccessI(String sName,long nPos) throws IOException `$B3X
{ 82]vkU
oSavedFile = new RandomAccessFile(sName,"rw"); @)-$kk*
this.nPos = nPos; QCX8IIHG
oSavedFile.seek(nPos); H8`(O"V
} ea~:}!-P
7g(F#T?;'
* ;Cy=J+
public synchronized int write(byte[] b,int nStart,int nLen) RhvfC5Hq
{ .?!N^_ Ez3
int n = -1; ")!,ZD
try{ TW9WMId
oSavedFile.write(b,nStart,nLen); >$,y5 AJ&
n = nLen; ?zsB6B?;
} D*YM[sN`
catch(IOException e) vMs$ceq
{ `A,g] 1C:
e.printStackTrace (); X0M1(BJgGo
} hweaGL t0
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&_gTD
return n; ]Wq?H-B{
} S:x?6IDPC^
Eyh51IB.
U=o"32n+
} 9gEssTkts
=pznu+,
Z+StB15
/* }QsZ:J.
**SiteInfoBean.java ?&^?-S% p
*/ ryc& n5
package NetFox; 5n ^TRB
yH<$k^0r*
]+m/;&0
public class SiteInfoBean { V86Xg:?7
W5'3$,X9
,E$@=1)
private String sSiteURL; //Site's URL b77>$[xB
private String sFilePath; //Saved File's Path ( &frUQm
private String sFileName; //Saved File's Name }irn'`I
private int nSplitter; //Count of Splited Downloading File 6O22P?v
q9^
6Kj'ZyVL
public SiteInfoBean() )#}mH@
{//nSplitter的缺省值为5 8l"O(B'#Z
//default value of nSplitter is 5 4 8{vE3JY
this("","","",5); o8Z[+;
} "9bN+1[<
}=2;
hG_?8:W8HT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BnM4T~reOF
{ P@]8pIB0d^
sSiteURL= sURL; 7'-j%!#w
sFilePath = sPath; Jy aag-
sFileName = sName; 7HHysNB"w
this.nSplitter = nSpiltter; w?,M}=vg
\i[BP
'/I:^9
} P N*JR
7 ua6l[c
/n4pXT
public String getSSiteURL() jkF8\dR
{ }elH75[64
return sSiteURL; cM_Fp
} 4"vaMa
%G@5!|J
b`_w])Y@
public void setSSiteURL(String value) T`9-VX;`
{ (.Lrmf@hI7
sSiteURL = value; =D^TK-H
} Cj*-[EL<
8:.nEo'
EHlytG}@
public String getSFilePath() &-1./?
{ XTDE53Js&
return sFilePath; Fn^C{p^
} s(_+!d6
w^1Fi8+
IF@HzT;Q
public void setSFilePath(String value) K"2|[5
{ ?_`0G/xl
sFilePath = value; 'ho{eR@d
} ap}5ElMR
PVao
Be}$I_95\P
public String getSFileName() y>\S@I
{ o;[bJ Z\^x
return sFileName; -n*;W9
} oY`qInM_
.~}z4r
)h^NR3N
public void setSFileName(String value) \O7J=6fn
{ M@p"yq
sFileName = value; a)2yE,":
} (3*UPZv
nEy]`
CQODXB^
public int getNSplitter() eFTX6XB:i
{ gUB{Bh($Y
return nSplitter; =z:U~D
} |xr32gs
J fcMca
wUi(3g|A
public void setNSplitter(int nCount) zzvlI66e
{ zL s^,x
nSplitter = nCount; ~_!ts{[E
} SvK1.NUa
} r9ke,7?
^Y^"'"
S=gW(c2'
/* DM3B]Yl
**Utility.java S2$5!(P
*/ "7?js $
package NetFox; gZ(O)uzv
6CNS%\A
)-&nxOP
public class Utility { ~SVQ;U)-
)LswSV
2H&{1f\Bf
public Utility() BV9*s
{ Ugi5OKdj7)
MWq$AK]
'7nJb6V,0l
} _1JmjIH)M
~4s-S3YzaM
//线程睡眠 5_G'68;OV
public static void sleep(int nSecond) C<he4n.
{ o_yRn16
try{ 3kLOoL?
Thread.sleep(nSecond); #t5juX9Ho9
} I=YCQ VvA
catch(Exception e) <`JG>H*B6
{ Ea`OT+#h(*
e.printStackTrace (); ?~qC,N[
} Qp&?L"U)2
} {v+a!#{c7
|h1^Gv
//日志 II#
public static void log(String sMsg) ~yN(-I1P
{ /v&`!nKu
System.err.println(sMsg); q<}PM
} H!JWc'(<$
n.;3X
I2*oTUSik
public static void log(int sMsg) Xr2J:1pgg
{ b@-)Fy4d2
System.err.println(sMsg); _z:Qhe
} ^@ UjQ9[>
} &V;x 4
n49s3|#)G
YnxU(v'\
/* pU[K%@sC
**TestMethod.java u.&|CF-
*/ gCwt0)
package NetFox; 7h1"^}M&
ZX]A )5G
j}RM.C\7
public class TestMethod { Ko-QR(
^HoJ.oC/
MVuP |&:n
public TestMethod() %9YA^ri
{ ///xx/weblogic60b2_win.exe &O{t^D)F
try{ mE_iS?1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C!kbZTO[p"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &u4Ve8#
SiteFileFetch fileFetch = new SiteFileFetch(bean); M[vCpa
fileFetch.start(); `L">"V`$Bj
} c8tP+O9
catch(Exception e){e.printStackTrace ();} q\G{]dz?R
,"C&v~
" V/k<HRw
} PJ6$);9}6
[sptU3,2U
^1vq{/ X
public static void main(String[] args) }(rzH}X@
{ ?bCTLt7k
new TestMethod(); fX$6;Ae
} `v<f}
} 2PI #ie4
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