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)); M(:bM1AD`u
} It/hXND`
for(int i=0;i<nEndPos.length-1;i++) xLLTp7b(
{ K7.ayM 0
nEndPos = nStartPos[i+1]; 0UW_ Pbh6
} f Ayh9
nEndPos[nEndPos.length-1] = nFileLength; n[r1h=?j3
} PhV/WjCZ
} w1(5,~OB
BNA1"@9q
@8w5Oudvx
//启动子线程 1*$6u5.=F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; | oM`
for(int i=0;i<nStartPos.length;i++) =./PY10'
{ (x@J@ GP*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P*>?/I`G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,quUGS
nStartPos,nEndPos,i); /*BK6hc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1{]S[\F]
fileSplitterFetch.start(); $%!06w#u
} 0%;| B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {q+gm1iC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PX0N7L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n[qnrk*3 %
nEndPos = " + nFileLength); ]N0B.e~D
// fileSplitterFetch[nPos.length-1].start(); WlY\R>x#
\6.dGKK
\o3s&{+y,
//等待子线程结束 ?/5<}W#7}
//int count = 0; C`3XOth
//是否结束while循环 Wd(|w8J{a
boolean breakWhile = false; 'rFLG+W
]]`[tVaFr
Y*Ay=@z=y
while(!bStop) 23K#9!3
{ =B'Yx
write_nPos(); O'^AbO=,
Utility.sleep(500); #nft{AN
breakWhile = true; QhAYCw2
dD'KP4Io@
<;>k[P'
for(int i=0;i<nStartPos.length;i++) D'{o3Q,%K
{ sAs`O@
if(!fileSplitterFetch.bDownOver) EV* |\ te
{ mr_NArF
breakWhile = false; X|g5tnsj`
break; J8@+)hn
} |a /cw"
} j5[>HL
if(breakWhile) f*hnzj
break; ;Z;` BGZJ
@n9iOf~<
2v4&'C
//count++; \>w 2D
//if(count>4) RLLL=?W@
// siteStop(); x2l}$(7
} JlE+CAny
$(OL#>9Ly
$gk=~p|
System.err.println("文件下载结束！"); " ;8kKR
} fHI@' '0
catch(Exception e){e.printStackTrace ();} c^&:':Z%'
} -%[6q
xs"\c7pC
(f#{<^gd
//获得文件长度 *>o@EUArN
public long getFileSize() ,s@S`KS0
{ Bv%dy[I
int nFileLength = -1; G"vEtNoV
try{ cj[%.M5iBA
URL url = new URL(siteInfoBean.getSSiteURL()); RzLeR%O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V|nJ%G\
httpConnection.setRequestProperty("User-Agent","NetFox"); [E}pU8.t6
pf=CP%L
!+Sd%2o
int responseCode=httpConnection.getResponseCode(); Fy_~~nI0
if(responseCode>=400) 5hAs/i9_
{ g^\>hjNX
processErrorCode(responseCode); Z$)jPDSr
return -2; //-2 represent access is error Zzr
} @XKVdtG
U/rFH9e$
gaL.5_1
String sHeader; HNfd[#gV
sNC~S%[
bGB5]%v,
for(int i=1;;i++) |X~vsM0
{ E `%*lGu_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "fd'~e$S#
//Utility.log(in.readLine()); <bBgevL+_K
sHeader=httpConnection.getHeaderFieldKey(i); @Z9>E+udQ
if(sHeader!=null) o-]8)G>~M
{ Pj*"2 LBW#
if(sHeader.equals("Content-Length")) r9^~I
{ NX<Q}3cC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S'AS,'EnY
break; kjR-p=}
} ^c>ROpic
} X.ZY1vO
else LO,k'gg<
break; BOW`{=
} Y2y = P
} H^w Inkf>
catch(IOException e){e.printStackTrace ();} G\S_e7$/
catch(Exception e){e.printStackTrace ();} 95 X6V
_,|N`BBqd
A4VVy~sd
Utility.log(nFileLength); YoRD9M~iG~
&uu69)u
",Fqpu&M
return nFileLength; G%fNGQwT
} ,6^V)F
}F)eA1
(k5d.E]CK
//保存下载信息（文件指针位置） Tn\59 (
private void write_nPos() }kb6;4>c
{ o7s<G8;?
try{ o_%gFV[q
output = new DataOutputStream(new FileOutputStream(tmpFile)); fhQ}Z%$
output.writeInt(nStartPos.length); ^Jn=a9Q6Z
for(int i=0;i<nStartPos.length;i++) KH76Vts
{ e!O:z
// output.writeLong(nPos); Je;HAhL
output.writeLong(fileSplitterFetch.nStartPos); *6P)HU@
output.writeLong(fileSplitterFetch.nEndPos); H=7Nh6v
} }h_= n>
output.close(); nM&UdKf3
} bmGtYv
catch(IOException e){e.printStackTrace ();} I r;Z+}4>Y
catch(Exception e){e.printStackTrace ();} O2>W#7
} 5NAB^&{Z<X
3D"?|rd~
e't1.%w
//读取保存的下载信息（文件指针位置） g7U>G=,;?U
private void read_nPos() F6 c1YI[
{ ]k.'~Syz
try{ SB2Ij',
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t:.ZvA3
int nCount = input.readInt(); H;rLU9b
nStartPos = new long[nCount]; Hs6}~d
nEndPos = new long[nCount]; .LHzaeJCX
for(int i=0;i<nStartPos.length;i++) 9$:+5f,%a
{ Stxrgmu
nStartPos = input.readLong(); naB`@
nEndPos = input.readLong(); @jevY81)
} ,}_uk]AQ
input.close(); 1brKs-z
} fE/|U|5L[
catch(IOException e){e.printStackTrace ();} ck4g=QpD{
catch(Exception e){e.printStackTrace ();} 1$G'Kg/
} &24z`ZS[w6
^L;k
/Jci1o
private void processErrorCode(int nErrorCode) !2Q>
{ f.SmCgG
System.err.println("Error Code : " + nErrorCode); @:"GgkyDl#
} GcYT<pwN6
gC qQ~lWZ
y()Si\9v
//停止文件下载 6C|]Fm
public void siteStop() '}q1 F<&
{ -P3;7_}]:h
bStop = true; ,"W.A
for(int i=0;i<nStartPos.length;i++) !,3U_!
fileSplitterFetch.splitterStop(); _C97G&
19t'
T{%'"mm;
} ?nAKB5=
} )c$)am\I{
//负责部分文件的抓取 eZWR)+aq
**FileSplitterFetch.java z.7'yJIP#
*/ rX<gcntv
package NetFox; #)xg$9LQb
].eY]o}=
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import java.io.*; 8?7gyp!k_f
import java.net.*; $ (gR^L
}w)`)N
hsUP5_
public class FileSplitterFetch extends Thread { k5@_8Rc
wCb%{iowH
P00pSRQHD
String sURL; //File URL F^]?'`7md
long nStartPos; //File Snippet Start Position 6/#5TdJA
long nEndPos; //File Snippet End Position &Tf R].
int nThreadID; //Thread's ID y=jTS
boolean bDownOver = false; //Downing is over plY`lqm
boolean bStop = false; //Stop identical (Rc0l;
FileAccessI fileAccessI = null; //File Access interface D=fB&7%@
q$Ol"K@
,Wp0,>!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2ju1<t,8)
{ 2rw<]Ce
this.sURL = sURL; e<p_u)m
this.nStartPos = nStart; Hf/2KYZ
this.nEndPos = nEnd; rGZ@pO2
nThreadID = id; Ccocv>=Q&J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [^gSWU
} $Q:5KNF+p
] 05Q4
(!';
public void run() >oc7=F<8lS
{ uREc9z`Q'
while(nStartPos < nEndPos && !bStop) B(MO!GNg=
{ \~
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UhCd,
try{ ,ASY &J5)7
URL url = new URL(sURL); Yb =8\<;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #U/B,`= >
httpConnection.setRequestProperty("User-Agent","NetFox"); hJ:Hv.{`)W
String sProperty = "bytes="+nStartPos+"-"; 1'_OM h*;
httpConnection.setRequestProperty("RANGE",sProperty); of& vQ
Utility.log(sProperty); '~ ]b;nA
<R{\pz2w
g6W.Gl"5\w
InputStream input = httpConnection.getInputStream(); C-6+ZIk4
//logResponseHead(httpConnection); m Xw1%w[*
iCx'`^HnP
{8jG6
byte[] b = new byte[1024]; 71/6=aq>n
int nRead; ?qK:P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &2\.6rb.
{ V,M8RYOnC!
nStartPos += fileAccessI.write(b,0,nRead); j#p3c
//if(nThreadID == 1) I3s}t$`y(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @pkozE-
} FySK&
xEiW]Eo
5d4-95['_
Utility.log("Thread " + nThreadID + " is over!"); n6uobo-
bDownOver = true; Yp ? 2<
//nPos = fileAccessI.write (b,0,nRead); &FanD
} .HtDcGp
catch(Exception e){e.printStackTrace ();} z(%Zji@!N
} *@Qt*f
} "1#,d#Q$
3> fuH'=
5g&'n
//打印回应的头信息 er<~dqZ}]
public void logResponseHead(HttpURLConnection con) Kc{wv/6}T
{ XnG!T$
for(int i=1;;i++) ?NwFpSB2
{ HxM-VK'
String header=con.getHeaderFieldKey(i); !9N%=6\
if(header!=null) igQyn|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1IsR}uLh
Utility.log(header+" : "+con.getHeaderField(header)); jf2E{48P
else !kz\ {
break; F%|(pHk
} JL$RBr
} a[JgR/E@x
;}PL/L$L6;
'\;tmD"N5#
public void splitterStop() 4@Qq5kpk*
{ fGfv{4R
bStop = true; %$}iM<
} /za,&7sf
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:H87x?e[
} 9PBmBP~
Q7s1M&K
lV1|\~?4
/* R3<+z
**FileAccess.java aG ,uF
*//文件访问(定位，写) G@;aqe[dB
package NetFox; Xgm7>=l
import java.io.*; AX)zSrXn
O| 2Q- @D
N$+"zJmw&
public class FileAccessI implements Serializable{ p)ONw"sb
Q9'p2@Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L9.#/%I\
RandomAccessFile oSavedFile; g,;MV7yE
long nPos; Uwp +w
wfdFGoy(
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public FileAccessI() throws IOException y{N9.H2
{ U!5@$Fu
this("",0); (X9V-4
} x\%egw
MXy{]o_H~
%L/=heBBd
public FileAccessI(String sName,long nPos) throws IOException bm4W,
{ dd$N4&
oSavedFile = new RandomAccessFile(sName,"rw"); 2 zy^(%a
this.nPos = nPos; %Z7!9+<
oSavedFile.seek(nPos); =T-w.}27O
} _x!pMj(A
]ok>PH]
I?>#neHc6
public synchronized int write(byte[] b,int nStart,int nLen) Y8PT`7gd`
{ q0~_D8e,
int n = -1; +[ItkfSod!
try{ AVp[gr
oSavedFile.write(b,nStart,nLen); a5-\=0L~
n = nLen; asg>TOW
} h,x]
catch(IOException e) IfcFlXmt2
{ :~(im_r
e.printStackTrace (); V%ch'
} W%1S:2+Kl
'T[zh#v>S
jO55<s94
return n; lIz_0rE
} z(3"\ ^T
O[!o1.
PlZiTP
} ]D%k)<YK
Wv"tAseu
GcR`{ 3hO
/* ??Zmj:8E'
**SiteInfoBean.java sh ;uKzQ
*/ E0Q"qEvU
package NetFox; 7g)3\C
F-^HN%
k`TJ<Dv;
public class SiteInfoBean { 91H0mP>ki
>Mw &Tw}o
|lxy< C4V
private String sSiteURL; //Site's URL ?Z>.G{Wm@
private String sFilePath; //Saved File's Path d|]O<]CG_
private String sFileName; //Saved File's Name J\3} il N
private int nSplitter; //Count of Splited Downloading File f_ztnRw
gE&W6z0fJ
v9U(sEDq
public SiteInfoBean() |QLX..
{//nSplitter的缺省值为5 wy{>gvqK
//default value of nSplitter is 5 N?;o_^C
this("","","",5); NRisr
} rxj@NwAno
J4"swPf
^Pd37&B4V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YM`pNtQ
{ ]<gCq/V#
sSiteURL= sURL; VONAw3k7!
sFilePath = sPath; liqR#<
sFileName = sName; ?[VpN2*
this.nSplitter = nSpiltter; $[iT~B$
dAr)%RZ
yv)nW::D(
} rEyz|k:
7B]:3M6d
H [Lt%:r
public String getSSiteURL() iv:/g|MBI&
{ HNy/ -
return sSiteURL; zk5=Opmvh
} wD],{y
pEVgJ/>
:X1cA3c!
public void setSSiteURL(String value) J+b!6t}mZn
{ 6I>5~?#
sSiteURL = value; 8b:clvh
} N3gNOq&
qX{X4b$
px|>v8
public String getSFilePath() ZP6x
{ 5U{4TeUH
return sFilePath; }B"|z'u
} dGsS<@G
r|^lt7\
8jggc#.
public void setSFilePath(String value) .vN%UNu
{ Er"R;l]xJ
sFilePath = value; 1GG>.RCP
} C[xJU6z
g={]Mzh
O xT}I
public String getSFileName() goDV2alC^
{ aGB0-;.t7
return sFileName; & =73D1A
} x*me'?q
\[hn]@@
vZb|!#I
public void setSFileName(String value) 5=Kq@[(4
{ 894r;UA7
sFileName = value; X!o[RJY
} 6| *(dE2x(
7~wFU*P1
=Kc|C~g
public int getNSplitter() |*^8~u3J"
{ *wC\w
return nSplitter; [)#u<lZ<~
} K,f* SXM
0A#*4ap
(9mbF%b
public void setNSplitter(int nCount) fav5e'[$
{ v:rD3=M-
nSplitter = nCount; >u=%Lz"J
} u64@"P
} U^%9 )4bj
AL>c:K)qO
X=v~^8M7%
/* 2E^"r jLm
**Utility.java izMYVI?0
*/ T/[f5?p
package NetFox; \un sh^M
.#*D!;f
b,#`n
public class Utility { <57g{e0I
Iq{o-nq
>n]oB~P%
public Utility() h`=r)D
{ hZcmP"wgC1
N99[.mErU
gs?8Wzh90*
} 5XDgs|8
^^%JoQ.
//线程睡眠 WFouoXlG0
public static void sleep(int nSecond) i8K_vo2Z)
{ FJ{=2]x|
try{ G'u|Q mb1
Thread.sleep(nSecond); dUIqDl
} 9I85EcT^4"
catch(Exception e) \.o=icOx
{ iHPUmTus--
e.printStackTrace (); W!t{rI72
} Uo~T'mA"
} kd yAl,
:vpl+)n
//日志 h\(B#SN
public static void log(String sMsg) ML=eL*}l
{ I!P4(3skAB
System.err.println(sMsg); "?35C !
} }`9jH:q-Z
9TC) w|
F>*{e
public static void log(int sMsg) 5$kdgFq(
{ S<"oUdkz
System.err.println(sMsg); oe9lF*$/
} Vz{>cSz#
} z`4c 4h]I
eIH$"f;L
dN< ,%}R
/* |#k@U6`SG
**TestMethod.java /2xSNalC
*/ ?E6^!4=,
package NetFox; c;9.KCpwx
KFU%DU G
Tg0CE60"
public class TestMethod { @ &pqt6/t
A|L'ih/
]W/>Ldv
public TestMethod() !J3UqS
{ ///xx/weblogic60b2_win.exe O(c@PJem
try{ <.bRf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r{_>ldjq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ! \sMR
SiteFileFetch fileFetch = new SiteFileFetch(bean); I-kWS4
fileFetch.start(); BEUK}T K4
} -R b{^/
catch(Exception e){e.printStackTrace ();} "j^MB)YD
bWmw3w
2:SO_O4C
} >P=Q #;v
d|lpec
Rko M~`CT
public static void main(String[] args) cj$d=k~
{ IeP WOpj3
new TestMethod(); dg_Gs>?2
} %S \8.
} <%P2qgz5
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