http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); 78<fbN5}r
} oz[G'[\}F
for(int i=0;i<nEndPos.length-1;i++) ;TwqZw[.
{ m5HMtoU
nEndPos = nStartPos[i+1]; kGakdLl
} S&k/Pc
nEndPos[nEndPos.length-1] = nFileLength; oYJ<.Yxeb
} cf*~Gx_l
} ]@}hyM[D;
TC@F*B;
!1]jk(Z
//启动子线程 s$0dLEa9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X &G]ci
for(int i=0;i<nStartPos.length;i++) JRE\R&>g
{ nr(C*E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -~H "zu`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ymnK`/J!Q
nStartPos,nEndPos,i); FP0GE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g:p`.KuB
fileSplitterFetch.start(); +JXn
} A_2lG!! 6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v;}MHl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CP$,fj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~3-+~y=o~
nEndPos = " + nFileLength); ?[WUix;
// fileSplitterFetch[nPos.length-1].start(); jMX|1b
P=y1qqC
3Q)"
//等待子线程结束 \8vZZt
//int count = 0; wsc=6/#u
//是否结束while循环 AUfcf*
boolean breakWhile = false; 0Jd>V
KF!d?
/len8FRf
while(!bStop) 3hzz*9/n
{ DiZv sc
write_nPos(); #!_ViG )2^
Utility.sleep(500); <KStlfX
breakWhile = true; d`j<Bbf-
+apn3\_
1}p:]/;
for(int i=0;i<nStartPos.length;i++) :3J`+V}9;
{ r/0AM}[!*j
if(!fileSplitterFetch.bDownOver) C{G%"q
{ yLl:G;
breakWhile = false; 8|+@A1)&4
break; LA(/UA3Izd
} j<9^BNl
} *<?KOM
if(breakWhile) ^?A>)?Sq
break; gd]_OY7L
N f}ZG
c`\qupnY
//count++; /N./l4D1K-
//if(count>4) p6Ia)!xOGF
// siteStop(); BE0Xg
} %;Z_`W
A,7* 52U
aqQ U7
System.err.println("文件下载结束！"); 0j}@lOt(
} (#qQ;ch
catch(Exception e){e.printStackTrace ();} 4CS$%Cu\?w
} 0fV}n:4Pq
?f!&M
e. E$Ej]w
//获得文件长度 zcio\P=^|B
public long getFileSize() `nc=@" 1
{ n*#HokX
int nFileLength = -1; _U,Hi?b"$}
try{ t+,2 p|B
URL url = new URL(siteInfoBean.getSSiteURL()); 0a,B&o1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UA4MtTp`
httpConnection.setRequestProperty("User-Agent","NetFox"); 9tmnx')_
GK3cQw
?]+!gz1
int responseCode=httpConnection.getResponseCode(); >J:liB|(
if(responseCode>=400) 8zjJshE/
{ _5OxESE
processErrorCode(responseCode); *hpS/g/3\
return -2; //-2 represent access is error R(f%*S4
} ndk~(ex|j
wawJZ+V
lt\Bm<"z!1
String sHeader; TpHzf3.I
p>+Q6o9O
B@' OUcUR
for(int i=1;;i++) [3x*47o"z
{ 20:![/7:!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <" 0b8 Z
//Utility.log(in.readLine()); P#rS.CIh
sHeader=httpConnection.getHeaderFieldKey(i); X'xnJtk
if(sHeader!=null) Ypinbej
{ (SA^>r
if(sHeader.equals("Content-Length")) $"6Gv
{ >3I|5kZ6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }1.'2.<Y
break; }5Km \OI
} $9W,1wg
} \GK]6VW
else crgVedx~}
break; #TB 3|=
} AyOy&]g
} :g+wv}z
catch(IOException e){e.printStackTrace ();} vVjk9_Ul
catch(Exception e){e.printStackTrace ();} /HdjPxH
J M;WCV%NM
hK %FpGYA
Utility.log(nFileLength); YmHu8H_Q
L}K8cB
o76{;Bl\O
return nFileLength; ,Z8)DC=
} &QFc)QP{
.F/s(
0="wxB
//保存下载信息（文件指针位置） ezS@`_pR;
private void write_nPos() s'BlFB n
{ l4U
try{ F4IU2_CnPD
output = new DataOutputStream(new FileOutputStream(tmpFile)); h&rZR`g
output.writeInt(nStartPos.length); Q9&H/]"v
for(int i=0;i<nStartPos.length;i++) fGWXUJ
{ ~{pds
// output.writeLong(nPos); "kjSg7m*:
output.writeLong(fileSplitterFetch.nStartPos); Y<_;8%S
output.writeLong(fileSplitterFetch.nEndPos); zu 7Fq]zD
} drbim8!q~
output.close(); eAjsMED
} ju1B._48
catch(IOException e){e.printStackTrace ();} |w5,%#AeO$
catch(Exception e){e.printStackTrace ();} {TDZDH
} ((=T E
aYc^ 9*7
!.499H3
//读取保存的下载信息（文件指针位置） !1Ht{cA0
private void read_nPos() wEQZ9?\
{ msQ?V&+<
try{ LG??Q+`l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B`)bo}h
int nCount = input.readInt(); _n&#e r
nStartPos = new long[nCount]; {HFx+<JG
nEndPos = new long[nCount]; 1Vs>G
for(int i=0;i<nStartPos.length;i++) 3^-\=taN<m
{ 7;pQ'FmZJ
nStartPos = input.readLong(); bRr3:"=sE
nEndPos = input.readLong(); F45-M[z
} /<Z3x _c
input.close(); Y8N+v+V/
} FuG;$';H75
catch(IOException e){e.printStackTrace ();} N*)O_Ki
catch(Exception e){e.printStackTrace ();} NCgKWyRR
} ,;f5OUl?[
F^5\w-gLY
F3L+X5D.yu
private void processErrorCode(int nErrorCode) LCuz_LTFq{
{ 2rb@Md]dx
System.err.println("Error Code : " + nErrorCode); =q*c}8R_0
} yet~
yD@1H(yM
69`*u<{PC
//停止文件下载 )"7z'ar
public void siteStop() d\25
{ #7KR`H
bStop = true; tYhcoV
for(int i=0;i<nStartPos.length;i++) D ,[yx='
fileSplitterFetch.splitterStop(); /QQjb4S}
RiFUa $
T`9nY!
} 6h0}ZM
} %pqB/
//负责部分文件的抓取 Zay%QNsb
**FileSplitterFetch.java $EzWUt
*/ {d.K)8\
package NetFox; 9!.S9[[N
;v/un
<~S]jtL.j:
import java.io.*; ~wO-Hgd
import java.net.*; dN7.W
N|3#pHm@
}$ Kd-cj+
public class FileSplitterFetch extends Thread { CTxP3a9]
{qOqtkj
CyXaHO
String sURL; //File URL }Yc5U,A;
long nStartPos; //File Snippet Start Position lQy-&d|=#^
long nEndPos; //File Snippet End Position |kTq &^$
int nThreadID; //Thread's ID :6/$/`I0W
boolean bDownOver = false; //Downing is over ^;tB,7:*V
boolean bStop = false; //Stop identical lS#^v#uS
FileAccessI fileAccessI = null; //File Access interface -!K&\hEjj
k|{ 4"4r
JpxQS~VX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GRaU]Z]ck
{ g's!\kr
this.sURL = sURL; D4uAwmc
this.nStartPos = nStart; %0Qq~J@Lu
this.nEndPos = nEnd; e1%kW1Z9
nThreadID = id; %?Q&a ]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^AiQNL}
} 6ud<U#\b&
>0uj\5h)I]
`6;$Z)=.
public void run() 5:C>:pAV
{ >s1?rC
while(nStartPos < nEndPos && !bStop) `5rfO6;
{ [HL>Lp&A?
xW2?\em
$?dQ^]<,
try{ XVJH>Zw
URL url = new URL(sURL); hljKBx~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L&~'SC
httpConnection.setRequestProperty("User-Agent","NetFox"); o8v,178
String sProperty = "bytes="+nStartPos+"-"; B9%%jEH*
httpConnection.setRequestProperty("RANGE",sProperty); =LGSywWM9
Utility.log(sProperty); g/i%XTX>
1 -C~C]&
;tF&r1
InputStream input = httpConnection.getInputStream(); R[)bGl6#
//logResponseHead(httpConnection); =;E0PB_w
9!kp3x/`
<q>d@Foi
byte[] b = new byte[1024]; )[|_q,
int nRead; h=JW^\?\]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yz5! >|EB
{ :@eHV=|+>
nStartPos += fileAccessI.write(b,0,nRead); q]VB}nO
//if(nThreadID == 1) 5G$ ,2i(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y*\N{6$2
} f=u +G
E!BzE_|i
~(7ct*U~
Utility.log("Thread " + nThreadID + " is over!"); _N)&<'lB<
bDownOver = true; 1iNMgA
//nPos = fileAccessI.write (b,0,nRead); =p"ma83
} p\9}}t7n
catch(Exception e){e.printStackTrace ();} w7&.Uqjf
} WglpWp)
} &%;n9K
o*ucw3s>
4nQ5zwiV
//打印回应的头信息 M ?AX:0
public void logResponseHead(HttpURLConnection con) 8FZC0j.^DH
{ s@{~8cHgU
for(int i=1;;i++) ^E:-Uy
{ .N@+Ms3
String header=con.getHeaderFieldKey(i); /y6f~F
if(header!=null) cza_LO(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2eA.04F
Utility.log(header+" : "+con.getHeaderField(header)); 3D1y^I
else ts}OE
break; GZKYRPg
} Yyr9Kj:
} -A=3W3:C
9q 2 vT^
*Ms"{+C
public void splitterStop() IkjJqz
{ 6x=w-32+ y
bStop = true; zSU,le
} oif|X7H;
4*Gv0#dga
41s\^'^&
} ZoSyc--Bv
:FfEjNil
f}p`<z
/* &/ED.K
**FileAccess.java RqP_^tB
*//文件访问(定位，写) RyG6_G}
package NetFox; B]:|;d
import java.io.*; ?6hd(^
q\|RI;W
:#35mBe}k
public class FileAccessI implements Serializable{ u[Si=)`VPk
`JpFqZ'58
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VJT /9O)Z|
RandomAccessFile oSavedFile; Y_n3O@,
long nPos; {"%a-*@%
E2YVl%.
\AH5zdK
public FileAccessI() throws IOException _cj=}!I
{ hliO/3g
this("",0); c$^v~lQS
} W5= j&&|!
EhM=wfGKw
_aF8Us
public FileAccessI(String sName,long nPos) throws IOException D,[Nn_N
{ ]'M B3@T
oSavedFile = new RandomAccessFile(sName,"rw"); UcOP 0_/
this.nPos = nPos; X0-PJ-\aD@
oSavedFile.seek(nPos); >u(^v@Ejf
} J:gC1g^
$I>]61l%
$/tj<++W
public synchronized int write(byte[] b,int nStart,int nLen) eq(h{*rC
{ WZPj?ou`G
int n = -1; cs.t#C
try{ xW*Lceb
oSavedFile.write(b,nStart,nLen); g,!.`[e'ex
n = nLen; H.E=m0np
} OFyy!r@?
catch(IOException e) lS7L|
{ cNxxX!P/
e.printStackTrace (); sxph#E%
} ,Xfu?Yan
]1Wxa?
cs*E9
return n; ~;H,cPvrEg
} 9d-'%Q>+
B["+7\c<~
/|i*'6*
} 2,`X@N`\
$fT5Vc]B4
f\_PNZCc
/* qlYi:uygY
**SiteInfoBean.java {FKr^)g
*/ *fIn<Cc
package NetFox; Skg/iH"(
D&2NO/ R
o{fYoBgr
public class SiteInfoBean { U5H%wA['m
TK[[6IB
njg0MZBqA
private String sSiteURL; //Site's URL n8=Dzv0
private String sFilePath; //Saved File's Path 8IQ}%|lN
private String sFileName; //Saved File's Name +hr|$
private int nSplitter; //Count of Splited Downloading File l!Xj UnRF
+~aIT=i3
9T5 F0?qd
public SiteInfoBean() ~ZSX84~@u
{//nSplitter的缺省值为5 LQ4:SV'3
//default value of nSplitter is 5 ZvT,HJ0?
this("","","",5); %<a3[TQd`\
} B ;E"VS0
9X=<uS
`y^\c#k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) amC)t8L?
{ Xb>SA|6[|
sSiteURL= sURL; H1B%}G*Ir-
sFilePath = sPath; T1.U (::
sFileName = sName; Q2r[^Z
this.nSplitter = nSpiltter; ;*j K!
Z'y&11
r(uo-/7z
} oxN5:)
La9}JvQoX
[BJzZ>cY
public String getSSiteURL() y$]<m+1
{ /7Pqy2sgE
return sSiteURL; xatq
} d4 \
6',Hs
zQ{bMj<S
public void setSSiteURL(String value) Wq<oP
{ 8P-ay<6
sSiteURL = value; `vAcCahM
} rDbtT*vN
JG'%HJ"D
i]? Eq?k
public String getSFilePath() 5;" $X 1{
{ h+j^VsP zB
return sFilePath; z{\tn.67
} `14@dk
}BI6dZ~2A
y,|2hrj/0E
public void setSFilePath(String value) s9CmR]C
{ MooH`2Fd
sFilePath = value; saiXFM7J
} ?Ce=h+l
S@u46X>
0m*b9+q
public String getSFileName() p{LbTjdNc
{ Q\kWQOB_
return sFileName; >zX^*T#
} Q;y5E`G
v/rBjUc+X
dt"/4wCO
public void setSFileName(String value) \L~^c1s3r
{ v9*+@
sFileName = value; 8CUtY9.
} :2S?|7U4
L+%kibnY'
Os$E,4,py
public int getNSplitter() upaP,ik}~
{ V.*M;T\i
return nSplitter; *1kFy_Gx
} aHuMm&
qKd ="PR}
*`u|1}h|
public void setNSplitter(int nCount) iw/~t
{ a'jUM+D;
nSplitter = nCount; TY %zw6 #p
} P}5bSQ( a3
} 1mJUlx
Z8bg5%
I]W7FZ=o
/* 7afG4 (<k
**Utility.java U?f-/@fc
*/ 83Rs1}*
package NetFox; H i8V=+
<#?dPDMG.*
Cfmd*,
public class Utility { dGOFSH
tmS2%1o
iu8Q &Us0P
public Utility() 96~y\X@x
{ 2?q>yL!Gz
gdTW ~b
]R)wBug
} ZwsQ}5
`9[n5-t
//线程睡眠 W7uX
public static void sleep(int nSecond) 5U7,,oyh
{ :stHc,
try{ .W~XX
Thread.sleep(nSecond); Ro9:kEG$
} 6Y]P7j
catch(Exception e) ,.ivdg(/
{ oOND]>
e.printStackTrace (); "y"oV[`
} &Hp*A^M
} (c)/&~aE
& tT6.@kH
//日志 `WL3aI":
public static void log(String sMsg) ~$K{E[^<
{ DL4`j>2Ov
System.err.println(sMsg); BuRsz6n
} ])F+ C/Px1
B7'#8heDh
$%bd`d*S
public static void log(int sMsg) F*J1w|)F0
{ DVhBZ!u9
System.err.println(sMsg); q&>fKSnKs
} 1O0. CC,p
} G) KI{D
hmkb!)
ZKEoU!
/* U"8Hw@
**TestMethod.java #2%V
*/ W|fE]RY
package NetFox; h.#:7d(g
8Snv, Lb`^
lq_UCCnv5
public class TestMethod { C=o-3w
,i}EGW,9q
M| Gl&
public TestMethod() hR|xUp
{ ///xx/weblogic60b2_win.exe ._tEDY/1m
try{ ;303fS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cSYCMQ1ro
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kB CU+FC
SiteFileFetch fileFetch = new SiteFileFetch(bean); -JEPh!oTt
fileFetch.start(); \K\eq>@6
} R7(XDX=[s
catch(Exception e){e.printStackTrace ();} 7Ji'7$
${z#{c1
MMKN^a"GA
} V1M|p!
`=hCS0F
*GXPN0^Qjo
public static void main(String[] args) Axb=1_--
{ ]QJ5JtD-
new TestMethod(); 7c(j1:Ku-
} ',`Qx{tQ)
} aE)1LP
点击下载更多相关资料