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)); 2I8RO\zR
} I3#h
for(int i=0;i<nEndPos.length-1;i++) JUf{;nt
{ `T-lBwH
nEndPos = nStartPos[i+1]; c`F~vrr)X
} 2l8TX#K
nEndPos[nEndPos.length-1] = nFileLength; 3;N+5*-
} tn"n~;Bh?:
} Hq>"rrVhx
H.n+CR
}Q=@$YIesD
//启动子线程 0Rme}&$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n#NE.ap$&,
for(int i=0;i<nStartPos.length;i++) ?HsQ417.H
{ ,X&(BQj h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .y)Y20=o!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XDot3)2`
nStartPos,nEndPos,i); "!fvEE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >h[ {_+
fileSplitterFetch.start(); A#WvN>
} SEL7,8 Hm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |?kZfr&9q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); miq"3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gvoo1 Sa
nEndPos = " + nFileLength); ThvVLK
// fileSplitterFetch[nPos.length-1].start(); e%B;8)7
Buv4&.Z}
ZjOUk;H?
//等待子线程结束 `;:zZ8*
//int count = 0; jP{W|9@(
//是否结束while循环 @S-p[u
boolean breakWhile = false; _6"YWR
-f4>4@y
.Lvg $d
while(!bStop) /.Fvl;!J;
{ ,pg\5b
write_nPos(); $PNS`@B
Utility.sleep(500); JyfWy
breakWhile = true; d{gj8
RH"&B`
.;:jGe(
for(int i=0;i<nStartPos.length;i++) /F3bZ3F
{ FTA[O.tiG
if(!fileSplitterFetch.bDownOver) X-Q;4M-CJ
{ /.[;u1z"^
breakWhile = false; 1>$}N?u:T
break; `4&a"`&$
} >o#^)LN
} ~kkwPs2V
if(breakWhile) ~I_v {
break; _i-(`5
IIrXI8'}
Z6`oGFq
//count++; n*HRGJ
//if(count>4) (16U]s
// siteStop(); ?9?eA^X%
} 1l~(J:DT
YXBU9T{r
(Vvs:h%H
System.err.println("文件下载结束！"); >`@c9 m
} tR;? o,T
catch(Exception e){e.printStackTrace ();} +(*;F4>
} itp$c|{
:Hn*|+'
XQH wu
//获得文件长度 #fb <\!iza
public long getFileSize() 5GwXZ;(G
{ N?7vcN+-t)
int nFileLength = -1; X53TFRxnT
try{ xD(RjL+
URL url = new URL(siteInfoBean.getSSiteURL()); Qxvj`Ge
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UB4M=R|
httpConnection.setRequestProperty("User-Agent","NetFox"); RgPY,\_9+
#4iiY6
#]BpTpRAe<
int responseCode=httpConnection.getResponseCode(); c T[.T#I
if(responseCode>=400) y'a(>s(
{ K?4/x4p@
processErrorCode(responseCode); xz#.3|_('
return -2; //-2 represent access is error +Yuy%VT
} /j{`hi
S!/N lSr<
&)8-iO
String sHeader; Gm]]Z_
@`</Z)
oQkY@)3.w
for(int i=1;;i++) g.cD3N
{ <MPoDf?h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )bM #s">Y
//Utility.log(in.readLine()); @rTAbEk{U
sHeader=httpConnection.getHeaderFieldKey(i); @\!9dK-W
if(sHeader!=null) icX$<lD
{ 6L2Si4OGjG
if(sHeader.equals("Content-Length")) Ww }qK|D
{ \[-z4Fxg|'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rRfPq
break; !*U#,qY
} xyoh B#'W
} Gob;dku
else ~4{E0om@
break; LGOeBEAMV^
} &SzLEbU!
} w'Kc#2
catch(IOException e){e.printStackTrace ();} ddR_+B*H
catch(Exception e){e.printStackTrace ();} 7\q_^
E rf$WPA
05|,-S
Utility.log(nFileLength); wc-ll&0Z
'pUJlPGx
6iozb~!Rr
return nFileLength; BBub'
} sF/X#GG-
"/EE$eU
*L%i-Wg"
//保存下载信息（文件指针位置） B>^5h?(lt
private void write_nPos() +UK".
{ )A`Zgg'L7D
try{ ]Tje6iF
output = new DataOutputStream(new FileOutputStream(tmpFile)); gAx8r-` `
output.writeInt(nStartPos.length); ) OqQz7'
for(int i=0;i<nStartPos.length;i++) -*?Y4}mK
{ I)$of9
// output.writeLong(nPos); )P{I<TBI;
output.writeLong(fileSplitterFetch.nStartPos); 5>XrNc91
output.writeLong(fileSplitterFetch.nEndPos); &zCqF=/9U
} /f_c?|
output.close(); -zeodv7
} [n`SXBi+n
catch(IOException e){e.printStackTrace ();} X9:(}=E V
catch(Exception e){e.printStackTrace ();} &wZ ggp
} I<w`+<o(
U`j[Ni}"
cU y,q]PO
//读取保存的下载信息（文件指针位置） [_3Rhp:
private void read_nPos() ZOFhX$I
{ a.|4`*1[;
try{ JlR'w]d M,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b&$ ?.z
int nCount = input.readInt(); =A6/D
nStartPos = new long[nCount]; 5(/ 5$u
nEndPos = new long[nCount]; >`jsUeS
for(int i=0;i<nStartPos.length;i++) Oc;/'d2
{ ?kICYtY:_b
nStartPos = input.readLong(); XA[GF6W,Y
nEndPos = input.readLong(); /!o(Y8e>x
} -%XvWZvZ
input.close(); u_aln[oIv
} dVDQ^O&
catch(IOException e){e.printStackTrace ();} 8ycmvpJ
catch(Exception e){e.printStackTrace ();} )shzJ9G
} O<R6^0B42
xM1>kbo|
W|U!kqU
private void processErrorCode(int nErrorCode) h(,SAY_
{ lu^c^p;
System.err.println("Error Code : " + nErrorCode); {&Kq/sRz
} 5zlgmCGow
q8:Z.<%8
9T47U; _)
//停止文件下载 4#5w^
public void siteStop() n9;+RhxA
{ vqLC?{i+
bStop = true; d[.kGytUt
for(int i=0;i<nStartPos.length;i++) WUid5e2
fileSplitterFetch.splitterStop(); /j]r?KAzw
@!\g+z_"
[aF?1KxNMt
} x@+m_y
} -aiQp@^/J
//负责部分文件的抓取 G"jKYW
**FileSplitterFetch.java q+{-p?;;
*/ U[zY0B
package NetFox; \lKiUy/
H_'i.t 'SS
YJw9 d]
import java.io.*; |Xblz1>DF
import java.net.*; IMY?L
d7A08l{
gmfux b/
public class FileSplitterFetch extends Thread { \s2hep
=2#a@D6Bl
i0uBb%GMT
String sURL; //File URL u93=>S
long nStartPos; //File Snippet Start Position 0(s0<9s%
long nEndPos; //File Snippet End Position d\`A ^
int nThreadID; //Thread's ID 0lNVQxG
boolean bDownOver = false; //Downing is over &nk6_{6 c
boolean bStop = false; //Stop identical B$k<F8!%
FileAccessI fileAccessI = null; //File Access interface 8T'=lTJ
P>=~\v nN#
=R#K`H66j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MN2#
{ cL&V2I5O
this.sURL = sURL; Q5e ,[1
this.nStartPos = nStart; /"?y @;Y~
this.nEndPos = nEnd; omM*h{z$$
nThreadID = id; |U?5% L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yhe$A<Rl=
} .~V0>r~my
w:Fi 2aJ
8uoFV=bj\
public void run() pez^]I
{ %3'4QmpR
while(nStartPos < nEndPos && !bStop) ~V?O%1)k?\
{ 9Ot;R?>(
U">D_ 8
GzK{.xf
try{ aG?ko*A;
URL url = new URL(sURL); 8WU UE=p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [~bfM6Jw
httpConnection.setRequestProperty("User-Agent","NetFox"); vy#n7hdCc
String sProperty = "bytes="+nStartPos+"-"; chsjY]b
httpConnection.setRequestProperty("RANGE",sProperty); \)VV6'zih
Utility.log(sProperty); 58*s\*V`\
DO(-)izC
%4U;Rdq&Ud
InputStream input = httpConnection.getInputStream(); hS&,Gm`^
//logResponseHead(httpConnection); L)VEA8}
a +Q9kh
0U]wEz*b
byte[] b = new byte[1024]; #NVtZs!V/
int nRead; 38!$9)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k,M%/AXd
{ 693J?Yah[
nStartPos += fileAccessI.write(b,0,nRead); I#Ay)+D
//if(nThreadID == 1) $rDeI-)S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @D8c-`LC"*
} :(?joLA
m;{_%oQ;
cj-P&D[Ny[
Utility.log("Thread " + nThreadID + " is over!"); eX9{wb(
bDownOver = true; qIK"@i[ uq
//nPos = fileAccessI.write (b,0,nRead); cD^n}'ej
} I,vy__sZ
catch(Exception e){e.printStackTrace ();} 7/NXb
} [P2$[|IM
} S =q.Y
3q
[AQ6ads)
//打印回应的头信息 XF(I$Mxl6
public void logResponseHead(HttpURLConnection con) Mn$TWhg'
{ aQwcPy|1R
for(int i=1;;i++) bC?uyo"
{ 8qn1?Lb
String header=con.getHeaderFieldKey(i); >/1N#S#9
if(header!=null) %\=5,9A\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8Cz_LyL
Utility.log(header+" : "+con.getHeaderField(header)); QRXsLdf$$
else CfQOG7e@
break; ./mh9ax
} bT}P":*y
} CQ2{5
EtJyI&7VK
z71.5n!C
public void splitterStop() = ^:TW%O
{ "T@9]>6.f
bStop = true; S*],18z?
} :Ts"f*
(=0W[@k
2}>jq8Y47
} rH8^Fl&jT
`GS!$9j
mJRvC%
/* <Bb$d@c
**FileAccess.java V(1Ldl'a
*//文件访问(定位，写) U 9TEC)
package NetFox; Lv+lLK
import java.io.*; EsXCi2]1
EP&iG%(k
:j9{n ,F
public class FileAccessI implements Serializable{ [Rw0']i`4
Ek(. ["
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FGu:8`c9
RandomAccessFile oSavedFile; VdQ}G!d
long nPos; !p4w 8
$[5ihV$u
y7dnXO!g9-
public FileAccessI() throws IOException 2]5dSXD
{ ,i#]&f`c;5
this("",0); "DM$FRI0
} s/UIo^m
+I#4+0f
z+FhWze
public FileAccessI(String sName,long nPos) throws IOException ~T>_}Q[M2p
{ r^-3( 77n
oSavedFile = new RandomAccessFile(sName,"rw"); q.FgX
this.nPos = nPos; 0e9W>J9
oSavedFile.seek(nPos); 1w'iD X
} 16)@<7b]J
|_8::kir:
g<{/mxv/
public synchronized int write(byte[] b,int nStart,int nLen) RK#e7
{ GrjL9+|x
int n = -1; _aL:XKM
try{ ^RrufwUA
oSavedFile.write(b,nStart,nLen); OaRtGJnR
n = nLen; Q*Per;%J
} pbKDtqSnz
catch(IOException e) |1X^@
{ ~Y@(
e.printStackTrace (); e4u$+
} qCOv4b`
>/nS<y>
VS@o_fUx)
return n; .cN\x@3-j
} (p26TN;*$5
%h 6?/
)Xg,;^
} H>_ FCV8
[tym~ZZ]_m
?~uTbNR
/* (h7 rW3
**SiteInfoBean.java HiCNs;t
*/ o{pQDI {R
package NetFox; eG9tn{
KL,=Z&.<=
3&_O\nD
public class SiteInfoBean { db`xlvrCY
\NKf$"x}
1s8v E f
private String sSiteURL; //Site's URL DhV($&*M
private String sFilePath; //Saved File's Path } *|_P
private String sFileName; //Saved File's Name BusD}9QqB
private int nSplitter; //Count of Splited Downloading File =HmV0
gN$.2+:
87c7p=/0`
public SiteInfoBean() ]WR+>)ERb
{//nSplitter的缺省值为5 /cF 6{0XS9
//default value of nSplitter is 5 {ER! 0w/
this("","","",5); SY>i@s+ML
} 4]A2Jl E
|8PUmax
`Gzukh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ))|Wm}
{ h2ewYe<87`
sSiteURL= sURL; Z0g3> iItM
sFilePath = sPath; ]N_(M
sFileName = sName; f1(V~{N,+
this.nSplitter = nSpiltter; c<L^ 1,G2
{[hH: \
*Uie{^p?
} 1%Xwk2l,8b
uFOxb}a9v
m5Q,RwJ!xK
public String getSSiteURL() 8o#*0d|
{ sufidi
return sSiteURL; _"SE^_&c
} Ke '?
n3t1'_/TU}
h 1G`z
public void setSSiteURL(String value) $'*@g1vY
{ i<&*f}='
sSiteURL = value; 7YsBwo
} >Lp^QP1gU
2ikY.Xi6
vJVL%,7
public String getSFilePath() @y3w_;P
{ =fG c?PQ
return sFilePath; =k6zUw;5 U
} }Iz'#I Xx
+gqtW86
\?7)oFNz
public void setSFilePath(String value) 0H,1"~,w]
{ tp<uN~rTgh
sFilePath = value; 3?SofPtc/
} xZW6Hk_
*CZvi0&
l4?o0;:)
public String getSFileName() %5V!Fdb
{ ['ol]ZJ
return sFileName; $Nvt:X_
} \GS]jhEtn
(G $nN*rlu
aKXaor@0f.
public void setSFileName(String value) 6*cG>I.Z
{ yG|^-O}L
sFileName = value; 5!u.w
} w^Qb9vTa8
ln%xp)t
J/S 47J~
public int getNSplitter() < .&t'W
{ [` ~YPUR*
return nSplitter; sG`||Kb;n
} 6wC|/J^
u}Vc2a,WV
s8Kf$E^?e.
public void setNSplitter(int nCount) gXN#<g,:^
{ ]Aap4+s
nSplitter = nCount; E;$)Oz
} >y)(M(o
} Ug02G
e\x=4i
<6^MVaD
/* {WUW.(^]G
**Utility.java y>wrm:b-O
*/ =<w6yeko
package NetFox; d!kiWmw,
6, \i0y5n
JR{3n*
public class Utility { <Z5ak4P
KD?~ hpg
`l,=iy$
public Utility() 6}^0/76^,
{ d2lOx|jt
4<._)_m
oR (hL4Dc
} 08AC9
{Ts@#V=:
//线程睡眠 N<o3pX2i]
public static void sleep(int nSecond) ._@Scd
{ vWY}+#
try{ BE. v+'c"
Thread.sleep(nSecond); i0DYdUj
} 1];rW`Bw
catch(Exception e) N"MK 0k
{ EeGP E
e.printStackTrace (); ModwJ w
} c#sPM!!
} z3+y|nx!
AY4ZU CqI
//日志 Q!K@
public static void log(String sMsg) |S48xsFvq
{ eUlF4l<]
System.err.println(sMsg); [^xLK
} xcdy/J&
{[WEA^C~Q
hZ|*=/3k
public static void log(int sMsg) eq.K77El{J
{ #g[jwl'
System.err.println(sMsg); N),bhYS]
} Qr]xj7\@i
} Q4e*Z9YJ
H&jK|]UXoO
Sx)b~*
/* $3>k/*=
**TestMethod.java ,JIjAm*2
*/ {a`t1oX(
package NetFox; Jj+|>(P
3 EH/6
wY|&qX,
public class TestMethod { W^; wr#
-=BQVJ_dK{
hJY= )
public TestMethod() [of{~
{ ///xx/weblogic60b2_win.exe D /ysS$!{
try{ vQB;a?)o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *sK")Q4N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j`jF{k b
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^FNvVbK|`
fileFetch.start(); rX*4$d0
} [kwVxaI
catch(Exception e){e.printStackTrace ();} )RA$E`!b
S^nshQI
eh_{-
} lc1?Vd$
=4`#OQ&g
|9>?{ B\a
public static void main(String[] args) LWgYGXWT"
{ >DX\^86x
new TestMethod(); F<SMU4]YdG
} vi?{H*H4c
} .OFwGOL%
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