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)); [_EZhq
} W:pIPDx1=!
for(int i=0;i<nEndPos.length-1;i++) #cI{Fe0h
{ ,s"^kFl
nEndPos = nStartPos[i+1]; p$]3'jw
} H&-zZc4\
nEndPos[nEndPos.length-1] = nFileLength; P/W XaE4
} T4Pgbop
} Q' {ML4
AP 2_MV4W
[1Qo#w1
//启动子线程 ivJ@=pd)B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8;JWK3Gv
for(int i=0;i<nStartPos.length;i++) n{argI8wF
{ x??+~$}\*-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t.i 8 2Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ia!y!_L\'
nStartPos,nEndPos,i); 286jI7T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'c9]&B
fileSplitterFetch.start(); .WZ^5>M-
} 4V)kx[j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oqO(PU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8e1UmM[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =O5pY9UO
nEndPos = " + nFileLength); aC8} d
// fileSplitterFetch[nPos.length-1].start(); -=)H{
f<d`B]$(
8Fz#A.%P
//等待子线程结束 .ypL=~Rp
//int count = 0; yEqps3%
//是否结束while循环 dy%;W%
boolean breakWhile = false; z!ZtzD]cb
<lPm1/8
)Q&(f/LT
while(!bStop) Z&+ g;(g
{ PUMXOTu]
write_nPos(); "c%0P"u
Utility.sleep(500); BLQ6A<
breakWhile = true; X9W@&zQ
823Y\x~>
O:;w3u7;u
for(int i=0;i<nStartPos.length;i++) Hw}Xbp[y
{ ;PF<y9M
if(!fileSplitterFetch.bDownOver) NX*Q F+
{ BU/"rv"(Fg
breakWhile = false; uP)'FI
break; u&Yz[)+b=g
} dd%6t
} 8Z8gRcv{p
if(breakWhile) u5`u>.!
break; z% ?+AM)P
)4e.k$X^
PbJ(:`u
//count++; ?Jm^<
//if(count>4) Cgk<pky1
// siteStop(); ]nn98y+
} &AeX
t%0VJB,Q2
EU/C@B2*Dl
System.err.println("文件下载结束！"); ?=Z?6fw
} HmGWht6R
catch(Exception e){e.printStackTrace ();} Uiw2oi&_
} C2kPMB=Xo
t\dN DS
@Md/Q~>
//获得文件长度 w3ResQ
public long getFileSize() ~g]Vw4pv
{ .5_2zat0H
int nFileLength = -1; T4Uev*A
try{ lgL%u K)
URL url = new URL(siteInfoBean.getSSiteURL()); AofKw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y'.p&QH'`
httpConnection.setRequestProperty("User-Agent","NetFox"); Woym/[i
pI\]6U
-l*|M(N\
int responseCode=httpConnection.getResponseCode(); i>`%TW:g
if(responseCode>=400) 4SxX3Fw
{ AO4U}?
processErrorCode(responseCode); k(nW#*N_
return -2; //-2 represent access is error z2~til
} s2V:cMXFn
`4J$Et%S
F v2-(
String sHeader; eu-*?]&Di
?dg[:1R}
k1~&x$G
for(int i=1;;i++) c7k~S-nU
{ zR:L!S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EI%89i`3^
//Utility.log(in.readLine()); S9y}
sHeader=httpConnection.getHeaderFieldKey(i); gPI ?C76
if(sHeader!=null) p8O2Z?\
{ Ffz,J6b
if(sHeader.equals("Content-Length")) kVMg 1I@
{ WSB0~+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <iC(`J$D
break; Ee! 4xg
} +7.',@8_V
} U%QI a TN*
else kbQ>a5`,x
break; E{`fF8]K
} 6%_nZvRv
} !*N@ZL&X
catch(IOException e){e.printStackTrace ();} jV1.Yz(`
catch(Exception e){e.printStackTrace ();} X.{S*E:$u
^6V[=!& H
cdT7 @
Utility.log(nFileLength); "<1{9
^}o2
f.$af4 u
return nFileLength; +a+Om73B2
} '-~~-}= sJ
l'_r:b
@qAS*3j
//保存下载信息（文件指针位置） fIU#M]Xx
private void write_nPos() VY4yS*y
{ _Y;W0Z
try{ YU'E@t5
output = new DataOutputStream(new FileOutputStream(tmpFile)); sUQ@7sTj
output.writeInt(nStartPos.length); bWU'cw
for(int i=0;i<nStartPos.length;i++) YNF k
{ {JMVV_}n
// output.writeLong(nPos); x'<X!gw
output.writeLong(fileSplitterFetch.nStartPos); +ye3HGD
output.writeLong(fileSplitterFetch.nEndPos); HIZe0%WPw
} xi}skA
output.close(); W^l-Y%a/o
} 9rf)gU3{+L
catch(IOException e){e.printStackTrace ();} OQJ6e:BGt
catch(Exception e){e.printStackTrace ();} j A%u 5V
} 2c*GuF9(0
BRiE&GzrF
NC(~l
//读取保存的下载信息（文件指针位置） &V/MmmT
private void read_nPos() SE %pw9
{ 2P0*NQ
try{ uKHxe~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4H&+dRI"
int nCount = input.readInt(); AoxA+.O
nStartPos = new long[nCount]; T_4/C2
nEndPos = new long[nCount]; ISvpQ 3{)s
for(int i=0;i<nStartPos.length;i++) 4^:=xL
{ UJ
nStartPos = input.readLong(); <RL]
nEndPos = input.readLong(); DB,J3bm
} 4Fr
input.close(); >z@0.pN]7
} PEZ!n.'S
catch(IOException e){e.printStackTrace ();} |yPu!pfl
catch(Exception e){e.printStackTrace ();} G"A#Q"
} utV_W&
w``U=sfmV
_H@DLhH|=
private void processErrorCode(int nErrorCode) 6D3B^.rj]
{ 'm$L Ij?@
System.err.println("Error Code : " + nErrorCode); 4j^ @wV'
} Xsa].
)8ZH-|N`!E
nX8v+:&}
//停止文件下载 sRb9`u=)
public void siteStop() tQ#n${a@f
{ ^U/O!GK
bStop = true; [Y`W
for(int i=0;i<nStartPos.length;i++) KMax$
fileSplitterFetch.splitterStop(); <N~K;n v
wUJcmM;
q!@4~plz
} ^S; -fYW2
} xyXa .
//负责部分文件的抓取 x kD6Iw
**FileSplitterFetch.java ~a2}(]
*/ N?8!3&TiV
package NetFox; v`T c}c '
Tp2.VIoQ=
<F'\lA9
import java.io.*; ~wdGd+ez
import java.net.*; ;$Jo+#
RxQ*
/yZcDK4
public class FileSplitterFetch extends Thread { ~"A0Rs=
Nz-&MS
|DwZ{(R"W
String sURL; //File URL rPm x
long nStartPos; //File Snippet Start Position #<xm.
long nEndPos; //File Snippet End Position |w3M7;~eF
int nThreadID; //Thread's ID kq-) ^,{y
boolean bDownOver = false; //Downing is over \w8\1~#
boolean bStop = false; //Stop identical DHRlWQox
FileAccessI fileAccessI = null; //File Access interface *m(=V1"
@2#lI
7t3!)a|lI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _Z\G5x
{ qe\5m.k
this.sURL = sURL; EdX$(scu~B
this.nStartPos = nStart; N$tGQ@
this.nEndPos = nEnd; G#$-1"!`
nThreadID = id; _yT Ed"$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |V(0GB
} w32y3~
U$UIN#
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public void run() W*Y/l~x}
{ $:^td/p J
while(nStartPos < nEndPos && !bStop) T u'{&
{ ),!qTjD
6S{l'!s'
-Qe'YBy:
try{ @(lh%@hO
URL url = new URL(sURL); n&!-9:0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {4PwLCy
httpConnection.setRequestProperty("User-Agent","NetFox"); rmOj
String sProperty = "bytes="+nStartPos+"-"; 1 -b_~DF
httpConnection.setRequestProperty("RANGE",sProperty); [fyLV`
Utility.log(sProperty); 1.>m@Slr>
ji="DYtL
VtohL+
InputStream input = httpConnection.getInputStream(); %}T6]S)%u
//logResponseHead(httpConnection); "Y.y:Vv;
V.2_i*
H"F29Pu2
byte[] b = new byte[1024]; FGkVqZ Y2?
int nRead; oL<St$1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qJw_
{ *K;~!P
nStartPos += fileAccessI.write(b,0,nRead); {c0`Um3&>
//if(nThreadID == 1) ss-D(K"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8cQ'dL`(
} t`QENXA}
%jM,W}2
*lb<$E]="!
Utility.log("Thread " + nThreadID + " is over!"); DaVa}
bDownOver = true; _ x*3PE
//nPos = fileAccessI.write (b,0,nRead); {xB3S_,8
} W{aY}`
catch(Exception e){e.printStackTrace ();} #A.@i+Zv
} tf G@&&%9
} :v 4]D4\o
j+YJbL v
WEpoBP CL
//打印回应的头信息 M^I(OuRMeI
public void logResponseHead(HttpURLConnection con) [00m/fT6
{ -K$)DvV^(E
for(int i=1;;i++) wQLSf{2
{ i mM_H;-X
String header=con.getHeaderFieldKey(i); 1:wQ.T
if(header!=null) w*Ihk)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tMe~vq[
Utility.log(header+" : "+con.getHeaderField(header)); GKCroyor
else ItCv.yv35
break; 92-I~ !d
} Y^]rMK/;
} h7@6T+#WoT
\Og+c%
QCJM&
public void splitterStop() 8>%hz$no=
{ 9>$p
bStop = true; v8DC21pb
} Wez5N
'ig'cRD6N
CQ2jP G*py
} w=@Dv
t:c.LFrF
M:V_/@W.
/* CH/rp4NeSy
**FileAccess.java rQ9'bCSr%
*//文件访问(定位，写) Ct|A:/z(
package NetFox; 5:Uso{
import java.io.*; F<w/PMb
'W#D(l9nI
:i7;w%B
public class FileAccessI implements Serializable{ XZwK6F)L
BluVmM3Vj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Vq2$'lY
RandomAccessFile oSavedFile; D3A/l
long nPos; rN{ c7/|
kNL\m[W8$
fn!KQ`,#
public FileAccessI() throws IOException QdC<Sk!G
{ %07SFu#
this("",0); {BHO/q3
} |WUG}G")*x
]:\dPw`A
?'je)F
public FileAccessI(String sName,long nPos) throws IOException bu"!jHPB
{ #o2[hibq
oSavedFile = new RandomAccessFile(sName,"rw"); D,ln)["xm
this.nPos = nPos; FCn_^l)EA
oSavedFile.seek(nPos); 6`-jPR
} 8x{'@WCG%
2Hv+W-6v
;S*}WqP,
public synchronized int write(byte[] b,int nStart,int nLen) <^uBoKB/f
{ sT' 5%4
int n = -1; RX5dO%
try{ YnP5i#"
oSavedFile.write(b,nStart,nLen); A+)`ZTuO
n = nLen; ri.I pRe
} FsryEHz
catch(IOException e) ?R#)1{(8d~
{ \^%}M!tan
e.printStackTrace (); C6y&#uX\
} !Rt>xD
:/Qq@]O>
I!?}jo3
return n; 2 Vrw
} *WT`o>
/FJu)H..U
e 3TI|e_
} 8&aq/4:q0
{.\TtE
O0y_Lm\
/* O1mKe%'|
**SiteInfoBean.java IN G@B#Cl
*/ N8FF3}> g
package NetFox; VU d\QR-
xF44M]i
&JI8]JmU)
public class SiteInfoBean { b>N8F^}~O
K6)j0]K1
Ez=Olbk
private String sSiteURL; //Site's URL UZsH9 o
private String sFilePath; //Saved File's Path !I Qck8Y
private String sFileName; //Saved File's Name zI<<Q2
private int nSplitter; //Count of Splited Downloading File e@OX_t_
f`=-US
hfy_3}_
public SiteInfoBean() d;}nh2*
{//nSplitter的缺省值为5 {,~3.5u
//default value of nSplitter is 5 Oo%d]8W
this("","","",5); N'`A?&2ru
} ;BIY^6,7e
/RC7"QzL
,Vk3kmuvr]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #?9;uy<j.q
{ v oj^pzZ
sSiteURL= sURL; Eg3q!J&Z
sFilePath = sPath; 'CkIz"Wd
sFileName = sName; 9j9TPyC/2
this.nSplitter = nSpiltter; :A'y+MnK<
7s{GbU\
?m?::RH
} nK%LRcAs
"~C,bk
3x'|]Ns
public String getSSiteURL() wx0j(:B]
{ O+Y6N
return sSiteURL; u($!z^h
} ` v@m-j6
4u5-7[TZ
*6DB0X_-}
public void setSSiteURL(String value) sI^Xb@'09$
{ wov\kV
sSiteURL = value; @'!SN\?W8
} 1F&Trqq
o="M
l3I:Q^x@
public String getSFilePath() =w 2**$
{ SmSH2m-
return sFilePath; ~gZLY ls
} k5.Lna
<+vw@M
{:$>t~=D
public void setSFilePath(String value) !\.pq 2
{ ")XHak.JX
sFilePath = value; GH:jH]u!V
} %.-4!vj
iN8zo:&Z
'XP7" N47O
public String getSFileName() V7fq4O^:
{ Cl8Cg~2
return sFileName; ieCEo|b
} Oso#+
!/i{l
!0LWa"
public void setSFileName(String value) dufu|BL|}
{ JL}_72gs
sFileName = value; 8_B4?` k
} 9} M?P
hVAn>_(
!1H# 6
public int getNSplitter() hxd`OG<gF
{ 'Nnzk
return nSplitter; peuZ&yK+"
} EPM-df!=
Y}|X|!0x
iYm-tsER;
public void setNSplitter(int nCount) PB`Y g
{ :L@?2),
nSplitter = nCount; q"sed]
} =O_4|7Zl
} }1i`6`y1
gANuBWh8T
Z|j>gq
/* *>'V1b4}
**Utility.java ipgC RHE
*/ =I;ZMJR
package NetFox; dx{bB%?Y\=
A,hJIe
j2.|ln"!
public class Utility { {19PL8B~}
)SRefW.v
A_ N;
public Utility() ?;+1)>{
{ a /l)qB#
Ln<`E|[29
lC("y' ::
} wyj{zWRJp
(\hx` Yh=>
//线程睡眠 vkd.)x`J,
public static void sleep(int nSecond) #9}D4i.`}
{ ~f1%8z
try{ xH(lm2kvT
Thread.sleep(nSecond); }`QUHIF
} wb5baY9
catch(Exception e) z.9U}F
{ ith 3=`3
e.printStackTrace (); K'Tm_"[u
} %.Fi4}+O
} RJ ||}5
NI}yVV
//日志 )=Z>#iH1
public static void log(String sMsg) gk[aM~p
{ nE&@Q
System.err.println(sMsg); (Hz^)5(~
} _jI,)sr4ic
+[AQUc
B^Nf #XN(
public static void log(int sMsg) eJVjuG
{ qL&[K>2z
System.err.println(sMsg); ?'Xj g#}<
} ]kG"ubHV?h
} #!qm ZN
YEs&
Ins`l
/* uK#4(eY=W
**TestMethod.java .TR9975
*/ KRLQ #,9
package NetFox; oMD>Ywc-
Lh"<XYY
>#;.n(y
public class TestMethod { w%VU/6~
tl4V7!U@^z
1N^[.=
public TestMethod() ^f &XQQY
{ ///xx/weblogic60b2_win.exe :O?MSS;~
try{ k\YG^I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yw[g!W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wd^':
SiteFileFetch fileFetch = new SiteFileFetch(bean); MS>Ge0P("~
fileFetch.start(); b#Z{{eLny
} *@r/5pM2}
catch(Exception e){e.printStackTrace ();} 5\sd3<:+
el<s8:lA
B5VKs,g
} mpEK (p
$s c
<#y[gTJ<'>
public static void main(String[] args) swoQ'
{ @=Uh',F
new TestMethod(); -.@r#d/
} eRstD>r
} }b"yU#`Q\
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